JP2005118756A - Inspection apparatus and inspection method for solution supply apparatus - Google Patents

Abstract

An object of the present invention is to provide an inspection apparatus which can easily inspect whether or not a solution is discharged from a nozzle of a solution supply apparatus.
In an inspection apparatus for inspecting whether or not a solution is ejected from each nozzle of a solution supply apparatus having a plurality of nozzles,
A CCD camera 21 that images the solution supply device and outputs a video signal, a synchronization signal extraction circuit 24 that extracts a vertical synchronization signal and a horizontal synchronization signal by inputting a video signal from the CCD camera, and the CCD A comparison circuit 26 to which a video signal from the camera is input through the synchronization signal extraction circuit, and a vertical synchronization signal and a horizontal synchronization signal from the synchronization signal extraction circuit are input, and input to the comparison circuit based on the input. A control device 27 for comparing a predetermined horizontal synchronizing signal of the video signal with a threshold value and counting a pulse signal equal to or higher than the threshold value included in the horizontal synchronizing signal to calculate the number of nozzles to which the solution is ejected; It comprises.
[Selection] Figure 1

Description

  The present invention relates to an inspection apparatus and an inspection method for a solution supply apparatus that supplies a solution to a substrate in the form of droplets by an inkjet method.

  Generally, in a manufacturing process of a liquid crystal display device or a semiconductor device, there is a film forming process for forming a circuit pattern on a substrate such as a glass substrate or a semiconductor wafer. In this film forming process, a functional thin film such as an alignment film or a resist is formed on the plate surface of the substrate.

  In the case of forming a functional thin film on a substrate, an ink jet type solution supply apparatus that ejects the solution for forming the functional thin film in a droplet form from a nozzle and supplies it to the plate surface of the substrate may be used.

  This solution supply apparatus has a transport table for transporting a substrate, and a plurality of heads each having a nozzle plate in which the nozzles are formed are substantially orthogonal to the transport direction of the substrate above the transport table. For example, they are arranged in a staggered manner along the direction of the movement. Thereby, a droplet-like solution is spray-applied from a plurality of nozzles on the upper surface of the substrate to be transported at a predetermined interval in a direction crossing the transport direction.

  Each nozzle is provided with a piezoelectric element facing each other through a flexible plate. When a predetermined voltage is applied to the piezoelectric element, the piezoelectric element expands and contracts, so that the portion of the flexible plate facing the piezoelectric element is deformed by the expansion and contraction, and the deformation causes the solution to be ejected from the nozzle toward the substrate. Will be supplied.

  By the way, several tens of nozzles are formed in one head. Since the nozzle has a very small diameter, it may become clogged due to drying of the solution. In addition, the characteristics of the piezoelectric element may change over time, or an abnormality may occur due to poor electrical contact. In such a case, since the solution may not be ejected from the nozzle where clogging or abnormality has occurred, the solution cannot be uniformly supplied to the substrate.

  Therefore, it is regularly inspected whether or not the solution is reliably ejected from a plurality of nozzles provided in the solution supply apparatus. Conventionally, such inspection is performed visually by an operator, or a solution supply device is imaged by an imaging device, and a solution is ejected from a nozzle, and an image obtained by the imaging device is digitally processed, so that all nozzles From this, it was determined whether or not the solution was being sprayed.

  By the way, in the method in which the operator visually inspects, since the droplets of the solution ejected from the nozzle are small and difficult to see, it is difficult to distinguish between the nozzle that is ejecting the solution and the nozzle that is not ejected. In addition, there was a bad work efficiency.

  In that respect, if the solution supply device is imaged by the imaging device and the imaged signal is subjected to image processing to determine whether or not the solution is being ejected from the nozzle, the certainty and efficiency of the work can be improved. It becomes possible.

  However, when image processing is performed on the image pickup signal of the image pickup apparatus, an expensive digital device is required to perform image processing, and thus there is a problem that the inspection apparatus is also expensive.

  The present invention provides a solution supply apparatus that can inspect whether or not a solution is being ejected from a nozzle of the solution supply apparatus efficiently and reliably with a relatively inexpensive configuration without performing image processing. An inspection apparatus and an inspection method are provided.

This invention is an inspection apparatus for inspecting whether or not a solution is ejected from each nozzle of a solution supply apparatus having a plurality of nozzles.
Imaging means for imaging the solution supply device and outputting a video signal;
A synchronization signal extraction circuit that extracts a vertical synchronization signal and a horizontal synchronization signal by inputting a video signal from the imaging means;
A comparison circuit to which a video signal from the imaging means is input via the synchronization signal extraction circuit;
A vertical synchronizing signal and a horizontal synchronizing signal from the synchronizing signal extraction circuit are input, and based on the input, a predetermined horizontal synchronizing signal of the video signal input to the comparing circuit is compared with a threshold value to generate the horizontal synchronizing signal. And a processing means for calculating the number of nozzles to which the solution is ejected by counting pulse signals that are equal to or greater than a threshold value.

  It is preferable that a filter for removing a noise component of the video signal that has passed through the synchronization signal extraction circuit is provided between the synchronization signal extraction circuit and the comparison circuit.

This invention is an inspection method for inspecting whether or not a solution is ejected from each nozzle of a solution supply apparatus having a plurality of nozzles.
An imaging step of imaging the solution supply apparatus;
A synchronization signal extraction step of extracting a horizontal synchronization signal and a vertical synchronization signal from the video signal obtained in this imaging step;
Comparing a predetermined horizontal sync signal with a threshold based on the extracted sync signal;
Based on a comparison between a predetermined horizontal synchronizing signal and a threshold value, the number of pulse signals equal to or higher than the threshold value included in the horizontal synchronizing signal is counted, and the number of nozzles to which the solution is ejected is calculated based on the counted number. A method for inspecting a solution supply apparatus comprising the steps of:

This invention is an inspection apparatus for inspecting whether or not a solution is ejected from each nozzle of a solution supply apparatus having a plurality of nozzles.
A plurality of vibration generating means that are provided to face each of the nozzles and vibrate when a solution sprayed from the nozzles collides;
Vibration detecting means for detecting whether or not each vibration generating means vibrates;
An inspection apparatus for a solution supply apparatus, comprising: a calculation unit that calculates the number of nozzles to which a solution has been ejected based on detection by the vibration detection unit.

This invention is an inspection apparatus for inspecting whether or not a solution is ejected from each nozzle of a solution supply apparatus having a plurality of nozzles.
A belt-like member that is stretched opposite to the solution supply device and is wound around the nozzle arrangement direction of the solution supply device and from which the solution is ejected.
An inspection of the solution supply apparatus, comprising: a detecting unit that images a portion of the belt-like member from which the solution is jetted and detects the nozzle that jets the solution to the belt-like member based on the imaging result. In the device.

  According to the present invention, since it is determined whether or not the solution is being ejected from the nozzle of the solution supply device based on the video signal from the imaging means, it is possible to reliably check whether or not the solution is being ejected from the nozzle with a simple device. Can be performed.

  FIG. 1 shows an inspection apparatus for a head 1 constituting a solution supply apparatus. The head 1 includes a head main body 2 as shown in FIGS. The head main body 2 is formed in a cylindrical shape, and its lower surface opening is closed by a flexible plate 3. The flexible plate 3 is covered with a nozzle plate 4, and a liquid chamber 5 is formed between the nozzle plate 4 and the flexible plate 3.

  A liquid supply hole 6 communicating with the liquid chamber 5 is formed at one longitudinal end of the head body 2, and a supply pipe 6 a is connected to the liquid supply hole 6. A solution for forming a functional thin film such as an alignment film or a resist is supplied from the liquid supply hole 6 to the liquid chamber 5. Thereby, the liquid chamber 5 is filled with the solution.

  As shown in FIG. 4, a plurality of nozzles 7 are formed in the nozzle plate 4 in a zigzag pattern along a direction orthogonal to the transport direction of the substrate to which the solution is applied. A plurality of piezoelectric elements 8 are provided on the upper surface of the flexible plate 3 so as to face the nozzles 7 as shown in FIG.

  A drive circuit unit 9 is provided in the head body 2. A pulse voltage having a predetermined pulse width set by the pulse generator 10 is input to the drive circuit unit 9 as serial data. The drive circuit unit 9 converts serial data into parallel data, and distributes and applies a pulse voltage having a predetermined pulse width to each piezoelectric element 8. As a result, the piezoelectric element 8 expands and contracts and partially deforms the flexible plate 3, so that the solution is jetted and supplied to the upper surface of the substrate from the nozzle 7 positioned facing the piezoelectric element 8.

  A recovery hole 11 communicating with the liquid chamber 5 is formed at the other longitudinal end of the head body 2. A recovery tube 11 a is connected to the recovery hole 11. The solution supplied from the liquid supply hole 6 to the liquid chamber 5 can be recovered from the recovery hole 11.

  The inspection apparatus for inspecting the head 1 having the above-described configuration includes a CCD camera 21 as an imaging unit as shown in FIG. The CCD camera 21 includes an optical lens unit 21a and a solid-state imaging device 21b that converts an optical image from the optical lens unit 21a into an electric signal. The portion of the head 1 that is imaged by the optical lens unit 21a. Is illuminated by an illumination lamp 22.

  A video signal V is output from the CCD camera 21 that images the head 1. This video signal V is amplified by the first video amplifier 23 and input to the synchronization signal extraction circuit 24. A comparison circuit 26 is connected to the synchronization signal extraction circuit 24 via a filter 25, and control as processing means to which the vertical synchronization signal and the horizontal synchronization signal extracted by the synchronization signal extraction circuit 24 are input. A device 27 is connected.

  The video signal V input to the synchronization signal extraction circuit 24 includes a noise component due to light and dark of the imaging background, and the video signal V passes through the filter 25 so that the noise component is removed. It has become. 2A shows the waveform of the video signal V before entering the filter 25, and FIG. 2B shows the video signal V from which the noise component has been removed by passing through the filter 25. FIG.

  The video signal 26 from which the noise component has been removed and input to the comparison circuit 26 is compared with the threshold value S from the control device 27 for the horizontal synchronization signal. That is, when the solution is ejected from the nozzle 7 of the head 1 and the head 1 is imaged by the CCD camera 21, the solution ejected from the nozzle 7 is used as the pulse signal P as shown in FIG. appear.

  Therefore, as shown in FIG. 2 (c), if the control device 27 inputs a voltage value at which the pulse signal P can be detected as the threshold value S to the comparison unit 26, the comparison unit 26 uses the threshold. The number of pulses having a voltage greater than or equal to the value S is detected.

  An output signal from the comparison unit 26 is input to the control device 27 via the extraction circuit 28. The extraction circuit 28 receives a trimming signal T as a synchronization signal from the control device 27. Accordingly, the extraction circuit 28 designates one horizontal synchronization signal at a predetermined position, and the number of pulses equal to or greater than the threshold value S included in the predetermined horizontal synchronization signal is input to the control device 27 and counted. Is done.

  The video signal V amplified by the first video amplifier 23 is amplified by the second video amplifier 31 and input to the second synthesis circuit 32. Similarly to the extraction circuit 28, the trimming signal T is input to the second synthesis circuit 32 from the control device 27.

  Further, a first synthesis circuit 33 is connected to the second synthesis circuit 32. An oscillation signal H from the oscillation circuit 34 is input to the first synthesis circuit 33, and a permission signal K is input from the control device 27 at a predetermined timing. When the permission signal K is input to the first synthesis circuit 33, the oscillation signal H from the oscillation circuit 34 is input from the first synthesis circuit 33 to the second synthesis circuit 32.

  The oscillation signal H is superimposed on a predetermined horizontal synchronization signal designated by the trimming signal T of the video signal V amplified by the second video amplifier 31 and input to the second synthesis circuit 32. Therefore, if the video signal V from the second synthesizing circuit 32 is displayed on the monitor 34, the predetermined horizontal synchronizing signal designated by the trimming signal T can be visually confirmed by the oscillation signal H. Become. That is, the vertical position on the monitor 35 of the horizontal synchronization signal specified by the trimming signal T and counted by the extraction circuit 28 and counting the number of pulse signals P equal to or greater than the threshold value S can be visually recognized.

  As described above, the inspection apparatus having the above configuration images the head 1 with the CCD camera 21 and outputs the horizontal synchronization signal designated by the trimming signal T from the control device 27 out of the video signal V from the CCD camera 21. Compared with the threshold value S, the pulse signal P equal to or higher than the threshold value S included in the horizontal synchronizing signal, that is, the number of nozzles 7 of the head 1 on which the solution is ejected is counted.

  Therefore, if the count result in the control device 27 is output to, for example, a personal computer, among the plurality of nozzles 7 provided in the head 1, the nozzles 7 on which the solution is ejected and the nozzles 7 on which the solution is not ejected are displayed. Can be identified. Therefore, by checking the clogged state of the nozzle 7 where the solution is not ejected or checking the quality of the piezoelectric element 8 based on the inspection result, the nozzle 7 where the solution is not ejected can be eliminated.

  That is, according to the inspection apparatus of the present invention, it is possible to perform an inspection by a relatively simple method in which whether or not the solution is ejected from the nozzle 7 of the head 1 by the video signal V from the CCD camera 21 is processed in an analog manner. Therefore, the apparatus can be made cheaper and simpler than the digital method in which the image pickup signal from the CCD camera 21 is processed and inspected.

  The oscillation signal H from the oscillation circuit 34 is input to the second synthesis circuit 32, and the position of the horizontal synchronization signal where the number of pulse signals P equal to or greater than the threshold S is counted by the control device 27 is displayed on the monitor 35. I tried to make it. Therefore, in the image G of the head 1 portion projected on the screen of the monitor 35, the position of the horizontal synchronizing signal used for the inspection of the head 1 can be visually recognized by the oscillation signal H.

  If the position of the horizontal synchronizing signal can be visually recognized by the monitor 35, the horizontal synchronizing signal used for the inspection of the head 1 is adjusted on the screen by adjusting the trimming signal T output from the control device 27 while looking at the monitor 35. It is possible to set a desired position in the vertical direction. As a result, it is possible to inspect the droplet-like solution that is ejected from the nozzle 7 and drops at an optimal position that does not shake in the direction intersecting the dropping direction, thereby improving the inspection accuracy. be able to.

  FIG. 5 shows a second embodiment of the present invention. In the inspection apparatus shown in this embodiment, a plurality of thread-like members 41 stretched at intervals corresponding to the plurality of nozzles 7 formed on the head 1 are positioned below the head 1. One end of the thread-like member 41 is fixed to the fixing portion 42, and the other end is fixed to a piezoelectric element 43 as vibration generating means.

  When the solution is discharged from the nozzle 7, the solution collides with the thread-like member 41 positioned corresponding to the nozzle 7. Since the thread-like member 41 vibrates when the solution collides, a voltage is generated in the piezoelectric element 43 by the vibration. The output from each piezoelectric element 43 is input to a voltage detector 44 as detection means.

  Therefore, by detecting whether or not each thread-like member 41 vibrates by the voltage detector 44, it is possible to detect the nozzle 7 from which the solution is discharged and the nozzle 7 from which the solution is not discharged.

  FIG. 6 shows a third embodiment of the present invention. In the inspection apparatus shown in this embodiment, a belt-like member 51 such as paper is stretched endlessly between a driving roller 52 and a pair of driven rollers 53. The belt-like member 51 travels by driving the drive roller 52 to rotate by a drive source (not shown).

  The belt-like member 51 has a horizontal portion 51 a that travels horizontally between the drive roller 52 and one driven roller 53. The horizontal portion 51 a is positioned below the head 1, and the imaging camera 54 is disposed downstream of the head 1 in the traveling direction of the belt-like member 51.

  The solution is discharged from each nozzle 7 of the head 1 to the horizontal portion 51 a of the band-shaped member 51. Next, the belt-like member 51 is caused to travel in the direction of the arrow by the driving roller 52, and the portion facing the head 1 is positioned within the field of view of the imaging camera 54. Then, when the band-shaped member 51 is imaged by the imaging camera 54, and the image signal is processed to confirm the spot (stain) of the solution adhering to the band-shaped member 51, the nozzle 7 from which the solution was discharged and the nozzle that was not discharged 7 can be discriminated.

  The belt-like member 51 is not limited to the configuration shown in FIG. 6, and although not shown, the belt-like member 51 is wound around the supply roller and is wound around the take-up roller. You may make it make it.

The book figure which shows the inspection apparatus of 1st Embodiment of this invention. (A) is a figure which shows the video signal before processing by a filter, (b) is a figure which shows the video signal after processing by a filter, (c) is a figure which shows a pulse signal and a threshold value. The longitudinal cross-sectional view of a head. The bottom view of a head. Schematic of the inspection apparatus which shows 2nd Embodiment of this invention. Schematic of the inspection apparatus which shows the 3rd Embodiment of this invention.

Explanation of symbols

  7 ... Nozzle, 21 ... CCD camera (imaging means), 24 ... Synchronization signal extraction circuit, 25 ... Filter, 26 ... Comparison circuit, 27 ... Control device (processing means).

Claims (5)

In the inspection apparatus for inspecting whether or not the solution is ejected from each nozzle of the solution supply apparatus having a plurality of nozzles,
Imaging means for imaging the solution supply device and outputting a video signal;
A synchronization signal extraction circuit that extracts a vertical synchronization signal and a horizontal synchronization signal by inputting a video signal from the imaging means;
A comparison circuit to which a video signal from the imaging means is input via the synchronization signal extraction circuit;
A vertical synchronizing signal and a horizontal synchronizing signal from the synchronizing signal extraction circuit are input, and based on the input, a predetermined horizontal synchronizing signal of the video signal input to the comparing circuit is compared with a threshold value to generate the horizontal synchronizing signal. And a processing means for calculating the number of nozzles to which the solution is ejected by counting pulse signals greater than or equal to a threshold value included therein.   2. The solution supply apparatus according to claim 1, wherein a filter for removing a noise component of a video signal that has passed through the synchronization signal extraction circuit is provided between the synchronization signal extraction circuit and the comparison circuit. Inspection equipment. In the inspection method for inspecting whether or not the solution is ejected from each nozzle of the solution supply apparatus having a plurality of nozzles,
An imaging step of imaging the solution supply apparatus;
A synchronization signal extraction step of extracting a horizontal synchronization signal and a vertical synchronization signal from the video signal obtained in this imaging step;
Comparing a predetermined horizontal sync signal with a threshold based on the extracted sync signal;
Based on a comparison between a predetermined horizontal synchronizing signal and a threshold value, the number of pulse signals equal to or higher than the threshold value included in the horizontal synchronizing signal is counted, and the number of nozzles to which the solution is ejected is calculated based on the counted number. A method for inspecting a solution supply apparatus, comprising the steps of: In the inspection apparatus for inspecting whether or not the solution is ejected from each nozzle of the solution supply apparatus having a plurality of nozzles,
A plurality of vibration generating means that are provided to face each of the nozzles and vibrate when a solution sprayed from the nozzles collides;
Vibration detecting means for detecting whether or not each vibration generating means vibrates;
An inspection device for a solution supply apparatus, comprising: a detection unit that detects a nozzle from which the solution is ejected based on detection by the vibration detection unit. In the inspection apparatus for inspecting whether or not the solution is ejected from each nozzle of the solution supply apparatus having a plurality of nozzles,
A belt-like member that faces the solution supply device and is provided so as to be able to be wound in a predetermined direction and from which the solution is jetted,
An inspection of the solution supply apparatus, comprising: a detecting unit that images a portion of the belt-like member from which the solution is jetted and detects the nozzle that jets the solution to the belt-like member based on the imaging result. apparatus.

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