JP2011086496A - Organic el mask cleaning device, device for manufacturing organic el display, organic el display, and organic el mask cleaning method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To scan a laser beam with constant intensity on an organic EL mask without loss of the laser beam or using a special optical system. <P>SOLUTION: The organic EL mask cleaning device 1, for carrying out laser cleaning to remove an organic material attached on an organic EL mask 2 by scanning a laser beam L, includes a laser light source 41 for oscillating the laser beam L, an electric current supply part 44 for supplying current to oscillate the laser beam L to the laser light source 41, an intensity measurement unit 5 for measuring intensity of the laser beam L oscillated from the laser light source 41, and a laser control unit 45 making the intensity measurement unit 5 measure the intensity of the laser beam L at a timing to change the organic EL mask 2 to adjust electric current which the electric current supply part 44 supplies so as to have predetermined intensity for peeling off the organic material based on the measured intensity. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an organic EL mask cleaning apparatus, an organic EL display manufacturing apparatus, an organic EL display, and an organic EL display that remove organic materials adhering to the organic EL mask by scanning the organic EL mask with laser light. The present invention relates to a mask cleaning method.

  2. Description of the Related Art Organic EL (Electro Luminescence) displays are widely used as low power consumption, lightweight, and thin image display devices that do not require a backlight. As the structure, an organic EL thin film layer is laminated on a transparent glass substrate, and the organic EL thin film layer adopts a structure in which a light emitting layer is sandwiched between an anode layer and a cathode layer. The light emitting layer is often formed as a thin film by vapor-depositing an organic material on a glass substrate, and each pixel region constituting the display is divided into three to deposit organic materials of three colors of RGB. . Therefore, vapor deposition is performed using an organic EL mask (shadow mask) in which a large number of openings are formed in order to deposit different color organic materials (organic dye materials) in the three regions of each pixel. The deposition process of the light emitting layer is completed by depositing each color deposition material while shifting the organic EL mask by the pixel pitch.

  When performing the vapor deposition process, the organic material adheres not only to the glass substrate but also to the organic EL mask. Since the mask for organic EL is not used only for one vapor deposition process but is used repeatedly, if a vapor deposition material adheres to the mask for organic EL when performing the next vapor deposition process, a new glass substrate will be used. Vapor deposition material is transferred and contaminated. In addition, an organic material is deposited on edge portions of the openings formed in the organic EL mask so that the area of the openings is partially or entirely blocked. Of course, if the entire area of the opening is blocked, or even if the area of the opening changes due to partial blocking, the deposition accuracy when using the organic EL mask is significantly reduced and it can be used. Is not. Therefore, the organic EL mask is periodically cleaned (preferably after completion of one vapor deposition process) to remove the vapor deposition material.

  As cleaning of the organic EL mask, wet cleaning using a surfactant or the like is mainly performed. Wet cleaning is cleaning performed by supplying a liquid to the organic EL mask. However, the organic EL mask to be cleaned is an ultrathin metal plate on the order of microns (several tens of microns), and a large amount of damage such as distortion or deformation is caused to the organic EL mask by the action of liquid pressure during wet cleaning. Given. In addition, when wet cleaning is performed using chemicals such as surfactants, a chemical solution supply mechanism and a drainage treatment mechanism for processing used chemicals (drainage) are required, which complicates the mechanism and causes environmental pollution due to drainage. There is also a problem.

  On the other hand, Patent Document 1 discloses a technique relating to cleaning (laser cleaning) performed by irradiating an organic EL mask with laser light as cleaning without using a chemical solution for wet cleaning. By irradiating the metal organic EL mask with laser light, a peeling force is applied between the organic EL mask and the organic material. The technique of Patent Document 1 is to perform cleaning by removing the organic material from the organic EL mask by this peeling force. And the adhesive film is affixed on the mask for organic EL, and the cleaning process is performed by transferring the peeled organic material to an adhesive film.

JP 2006-169573 A

  As disclosed in Patent Document 1, when an organic EL mask (evaporation mask) is irradiated with laser light to peel off and remove an organic material (deposit), the organic EL mask has a laser with a predetermined intensity. You have to irradiate light. This predetermined intensity is an intensity set for peeling off the organic material. When a laser beam having an intensity higher than the intensity is irradiated, the organic EL mask is damaged, and an intensity lower than the intensity is applied. When the laser beam is irradiated, the organic material cannot be sufficiently peeled off. For this reason, it is necessary to irradiate the laser beam so as to always maintain a constant intensity.

  As a technique for maintaining the intensity of the laser light constant, APC (auto power control) is known in which a part of the laser light oscillated from the laser light source is extracted and the intensity of the extracted laser light is measured. Yes. By using this method, the intensity of the laser beam can always be detected, and when the intensity varies from the originally planned intensity, it can be detected and corrected. However, in this case, since a part of the laser beam is extracted, a loss occurs in the intensity of the laser beam, and a dedicated optical system for extracting a part of the laser beam (for example, a part of the laser beam is separated). A half mirror to be used).

  Accordingly, an object of the present invention is to scan a laser beam having a certain intensity on an organic EL mask without using a laser beam loss or a dedicated optical system.

  In order to solve the above-described problems, an organic EL mask cleaning apparatus according to claim 1 of the present invention scans a laser beam and performs laser cleaning to remove an organic material adhering to the organic EL mask. An apparatus comprising: a laser light source that oscillates the laser light; a power source that supplies a current for oscillating the laser light to the laser light source; and an intensity measurement that measures the intensity of the laser light oscillated from the laser light source. And the intensity measuring unit to measure the intensity of the laser light at the timing of exchanging the organic EL mask, and the intensity is set to peel off the organic material based on the measured intensity And a laser control unit that adjusts a current supplied by the power source.

  According to this organic EL mask cleaning apparatus, the intensity of the laser beam is measured at the timing of replacing the organic EL mask, and the current supply amount is adjusted. When the organic EL mask is replaced, the laser beam is not scanned, so that a part of the light amount is not lost when the laser beam is scanned, and it is not necessary to use a dedicated optical system.

  The organic EL mask cleaning device according to claim 2 of the present invention is the organic EL mask cleaning device according to claim 1, wherein the organic EL is disposed in a transport path of the organic EL mask of a cleaning stage for performing the laser cleaning. A mask detection sensor for detecting a mask for use, wherein the timing control unit causes the intensity measurement unit to perform intensity measurement at a timing detected by the mask detection sensor.

  According to the organic EL mask cleaning apparatus, by providing the mask detection sensor, it is possible to detect the loading / unloading of the organic EL mask and recognize the replacement timing. As a result, the timing for measuring the intensity of the laser beam can be controlled.

  The organic EL mask cleaning device according to a third aspect of the present invention is the organic EL mask cleaning device according to the first aspect, wherein the laser control unit and the intensity of the laser beam measured by the intensity measuring unit When the difference from the set intensity exceeds an allowable error, a warning unit is provided to warn to that effect.

  According to this organic EL mask cleaning apparatus, a warning is issued when the measured intensity of the laser beam deviates greatly from the set intensity. In this case, the life of the laser light source has been exceeded, and a warning that prompts replacement of the laser light source is issued. As a result, the laser light source is not continuously used even after the end of its life, and the laser light can be irradiated with a predetermined intensity.

  The organic EL mask cleaning device according to a fourth aspect of the present invention is the organic EL mask cleaning device according to the first aspect, wherein the laser control unit measures the current supplied by the power source and the intensity measuring unit. A life prediction unit that generates a current intensity characteristic by sampling a plurality of relationships with the intensity and predicts the replacement timing of the laser light source based on a difference between the current intensity characteristic and the ideal current intensity characteristic is provided. It is characterized by that.

  According to this organic EL mask cleaning apparatus, the replacement time of the laser light source is predicted using the current intensity characteristics. By comparing the current intensity characteristics obtained by sampling a plurality of data, it is possible to predict how much usable time of the laser light source is left, and it is possible to predict the replacement time in advance.

  According to a fifth aspect of the present invention, there is provided an organic EL display manufacturing apparatus comprising the organic EL mask cleaning apparatus according to any one of the first to fourth aspects. An organic EL display according to a sixth aspect of the present invention is manufactured by the organic EL display manufacturing apparatus according to the fifth aspect.

  The organic EL mask cleaning method according to claim 7 of the present invention is a method for cleaning an organic EL mask that performs laser cleaning to remove an organic material adhering to the organic EL mask by scanning laser light. The intensity of the laser beam is measured at the timing of replacing the mask, and the current supplied to oscillate the laser beam is adjusted based on the measured intensity so that the intensity is set to peel off the organic material. It is characterized by doing.

  In the present invention, the intensity of laser light is measured at the timing of replacing the organic EL mask, and the current supply amount is adjusted. Since the intensity is measured not at the timing of scanning the laser beam but at the replacement timing, it is not necessary to take out a part of the laser beam during scanning, so that no light loss occurs. In addition, since the intensity can be measured by irradiating all of the laser light, a dedicated optical system for extracting a part is not required, and the intensity can be measured with high accuracy. In addition, since the intensity measurement is performed using the time for replacing the organic EL mask, which is an essential operation in laser cleaning, there is no time loss.

It is a figure which shows schematic structure of the mask cleaning apparatus for organic EL. It is the side view and top view of an organic EL mask. It is a top view of a cleaning stage and an intensity measurement part. It is a block diagram which shows schematic structure of a laser control part. It is a graph which shows an electric current intensity characteristic. It is a flowchart for demonstrating operation | movement of this invention. It is a figure explaining the intensity | strength measurement of the laser beam in a measurement position. It is a figure explaining the scanning of a laser beam.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an organic EL mask cleaning apparatus 1 of the present invention. The organic EL mask cleaning device 1 is a device that performs laser cleaning (cleaning performed by scanning laser light) on the organic EL mask 2, and mainly includes a cleaning stage 3, a laser unit 4, and an intensity measuring unit 5. It has a general configuration.

  The organic EL mask 2 is an object to be cleaned that is cleaned using an organic EL mask cleaning device. As shown in FIG. 2, the organic EL mask 2 is an ultra-thin metal plate used for patterning by depositing an organic material (evaporation substance) as a light emitting layer on a glass substrate 20 constituting an organic EL display. It is. In order to deposit a vapor deposition substance on the glass substrate 20 with high accuracy, the thickness of the organic EL mask 2 is a very thin metal plate on the order of microns. As the size of the organic EL display is increased, the size of the organic EL mask 2 is also increased. For this reason, the organic EL mask 2 is an extremely thin and large metal plate.

  The organic EL mask 2 has a mask body 21 and is a mask metal plate (shadow mask) in which a large number of openings 22 regularly arranged in the mask body 21 are formed. Various materials can be used as the material of the organic EL mask 2, and here, a nickel alloy is applied. The organic EL mask 2 is made to deposit an organic material from a deposition source in a state of being in close contact with the glass substrate 20 in a vacuum deposition tank (not shown) for depositing the organic material of the light emitting layer.

  Various materials can be used as the evaporating material for the light emitting layer. For example, an organometallic complex such as an aluminum complex (trisaluminum: Alq) is used. Note that an organic compound other than the organometallic complex (which may or may not contain a metal) may be applied as a vapor deposition substance. The vapor deposition material evaporated from the vapor deposition source is deposited on the glass substrate 20 through the opening 22 of the organic EL mask 2. As a result, the vapor deposition material as the light emitting layer is deposited on the region corresponding to the pixel of the glass substrate 20 to form a pattern. Since the organic EL mask 2 is a large and extremely thin metal plate, as shown in FIG. 2, a reinforcing frame 23 is attached around the periphery thereof to provide shape retention. The reinforcing frame 23 may be a metal material or a material other than metal.

  When the vapor deposition process is performed once using the organic EL mask 2, the vapor deposition material adheres not only to the glass substrate 20 but also to the organic EL mask 2. Since the vapor deposition process is repeatedly performed, the cleaning of the vapor deposition material adhering to the organic EL mask 2 is performed at a predetermined timing (at least once per vapor deposition process). Since the cleaning tank in which the organic EL mask cleaning device is disposed and the vacuum deposition tank for vapor deposition on the glass substrate 20 are provided separately and independently, the organic EL mask 2 is used when performing the organic EL mask cleaning device. It is transferred from the vacuum deposition tank to the cleaning tank.

  The cleaning stage 3 will be described with reference to FIGS. 1 and 3. The cleaning stage 3 is a stage for performing laser cleaning on the organic EL mask 2. The cleaning stage 3 is based on a base 31, and a chuck portion 32 is provided on the base 31. The chuck portion 32 holds and fixes the periphery of the organic EL mask 2 and holds two sides in the example of FIG. Of course, it may hold three or four sides of the organic EL mask 2. When the organic EL mask 2 is fixedly held by the chuck portion 32, a minute gap is formed between the organic EL mask 2 and the base 31.

  The transition from the vacuum deposition tank to the cleaning tank is performed using robot means (not shown). The robot means is provided with a gripping means, and the organic EL mask 2 is carried in from the outside of the cleaning stage 3 with the organic EL mask 2 being gripped (in the X direction in FIG. 3). Then, after the organic EL mask 2 is fixedly held on the chuck portion 32, the robot means is retracted and laser cleaning is performed. After the laser cleaning is completed, the robot means receives the organic EL mask 2 again and carries it out of the cleaning stage 3 while holding the organic EL mask 2. The loading / unloading of the organic EL mask 2 may be performed by means other than the robot means, such as a moving table.

  In FIG. 3, the path for carrying in (loading) the organic EL mask 2 and the path for carrying out (unloading) the organic EL mask 2 are provided as the same path (conveyance path 33). That is, the organic EL mask 2 passes through the transport path 33 both at the time of carry-in and at the time of carry-out. Here, the carry-in route and the carry-out route are the same transport route 33, but they may be different routes. As shown in FIG. 3, mask detection sensors 34 are provided at two locations on the transport path 33. The mask detection sensor 34 monitors the upper part and detects that when the organic EL mask 2 passes. The mask detection sensor 34 may be provided at one place or at three or more places.

  The laser unit 4 will be described. As shown in FIG. 1, the laser unit 4 includes a laser light source 41, a galvano mirror 42, a galvano driving unit 43, a power supply 44, a laser control unit 45, and a unit moving unit 46. The laser light source 41 is a light source that oscillates the laser light L, and oscillates the laser light L in the Y direction in FIG. The laser light source 41 oscillates the laser light L by synchronizing the laser light L with a pulse having a short time width, that is, the laser light L becomes a pulse laser.

  A galvanometer mirror 42 is arranged in the direction in which the laser beam L is oscillated. The galvanometer mirror 42 is a reflection mirror that vibrates minutely at high speed, and reflects the laser light L toward the organic EL mask 2. When the galvanometer mirror 42 is vibrated minutely, the reflection direction slightly changes, so that the laser light L scans the organic EL mask 2. The galvano drive unit 43 is a drive unit that performs vibration control of the galvano mirror 42.

  The power supply 44 supplies current to the laser light source 41. The laser light source 41 oscillates the laser light L using a current supplied from the power supply 44 as a drive source. If the supplied current is large, the oscillation intensity of the laser beam L is high, and if the supplied current is small, the oscillation intensity of the laser beam L is low. The amount of current supplied by the power supply 44 is adjusted by the laser control unit 45. Details of the laser control unit 45 will be described later.

  The unit moving part 46 is a mechanism for moving the entire laser unit 4 in the Y direction in FIG. The unit moving unit 46 is a relative moving unit that relatively moves the cleaning stage 3 and the laser unit 4. Here, the laser unit 4 is provided with the unit moving part 46 and moved, but the cleaning stage 3 may be provided with a moving part and moved. In short, what is necessary is just to move the laser unit 4 and the cleaning stage 3 relatively.

  The intensity measuring unit 5 will be described. The intensity measuring unit 5 is provided outside the cleaning stage 3 and is connected to the base 31 via a connecting member 51. As shown in FIG. 3, the intensity measuring unit 5 is provided with a light receiving unit 52, and the light receiving unit 52 is irradiated with the laser light L to perform photoelectric conversion, whereby the intensity (power) of the laser light L is changed. Measuring.

  The laser control unit 45 will be described with reference to FIG. The laser control unit 45 includes a current intensity characteristic generation unit 61, a characteristic fluctuation amount calculation unit 62, an ideal characteristic storage unit 63, a fluctuation amount determination unit 64, an allowable fluctuation amount storage unit 65, a life prediction unit 57, a warning unit 66, and a current adjustment. A part 68 and a timing control part 69 are provided and schematically configured.

  The current intensity characteristic generation unit 61 inputs information (intensity information) of the intensity (unit: watts) of the laser beam L measured from the light receiving unit 52, and the current value when the laser beam L is oscillated from the power supply 44 ( Current value: Unit is amperage). The relationship between the intensity and current at this time is generated as a current intensity characteristic. The current intensity characteristic is obtained by changing the current value minutely (for example, every 0.1 watt) and measuring the intensity at that time, as shown in FIG. 5 (relationship between current and intensity). Curve) can be obtained. The width and range in which the current value is changed can be freely set.

  The generated current intensity characteristic is output to the characteristic fluctuation amount calculation unit 62. In addition, the characteristic variation calculation unit 62 inputs the ideal characteristic from the ideal characteristic storage unit 63. The ideal characteristic is an ideal current intensity characteristic of the laser light source 41, and the ideal characteristic storage unit 63 stores this ideal characteristic. The ideal characteristic is a current intensity characteristic inherent to the laser light source 41 obtained by measuring the relationship between current and intensity when the laser light source 41 is used for the first time. For this reason, when the laser light source 41 is used for the first time, the laser light L is irradiated from the laser light source 41 to the intensity measuring unit 5 to obtain a relationship between current and intensity. Then, by changing the current value slightly, an ideal characteristic as a current intensity characteristic in an ideal state such as a curve shown by a solid line in FIG. 5 can be obtained. Note that the current value characteristic may not be actually measured, and the design value may be used as long as the design value of the laser light source 41 is already set.

  The characteristic variation calculation unit 62 calculates the difference between the actually measured current intensity characteristic (characteristic generated by the current intensity characteristic generation unit 61) and the ideal specification, and the characteristic variation indicating how much variation has occurred in the current intensity characteristic. Get quantity. In the laser light source 41, the oscillation intensity decreases with the degree of use, and the current intensity characteristic gradually deteriorates. In FIG. 5, the current intensity characteristic deteriorated by use is shown by a one-dot chain line, and the difference between the ideal characteristic and the measured current intensity characteristic, that is, the difference between the solid line and the one-dot chain line in FIG. The calculated characteristic fluctuation amount is output to the fluctuation amount determination unit 64. The fluctuation amount determination unit 64 compares the allowable fluctuation amount stored in the allowable fluctuation amount storage unit 65 with the characteristic fluctuation amount, and determines whether or not the characteristic fluctuation amount exceeds the allowable fluctuation amount.

  The characteristic fluctuation amount is a fluctuation amount of the current intensity characteristic with respect to the ideal characteristic, and this characteristic fluctuation amount has an allowable error. This allowable error indicates the life (usable time) of the laser light source 41. When the allowable error is exceeded, the laser light source 41 cannot be used continuously. That is, this tolerance becomes a threshold value indicating the replacement time of the laser light source 41. The allowable error is arbitrarily set depending on the type of the laser light source 41. For example, a characteristic variation amount of ± N (N is a natural number less than 100)% can be set as an allowable error.

  When the fluctuation amount determination unit 64 determines that the characteristic fluctuation amount exceeds the allowable fluctuation amount, the fact is output to the warning unit 66. In this case, since the laser light source 41 has reached the end of its life, the laser light source 41 must be replaced. The warning unit 66 issues a warning for recognizing the replacement time. As a warning method, an alarm sound may be sounded or a message to that effect may be displayed on a display unit such as a display. Using this warning as a trigger, for example, a maintenance staff exchanges the laser light source 41.

  On the other hand, when the fluctuation amount determination unit 64 determines that the characteristic fluctuation amount does not exceed the allowable fluctuation amount, the characteristic fluctuation amount information is output to the life prediction unit 67. Since the characteristic fluctuation amount is a fluctuation amount between the ideal characteristic and the actually measured current intensity characteristic, the replacement timing of the laser light source 41 can be predicted based on the fluctuation amount. As shown in FIG. 5, the curve indicating the current intensity characteristic is substantially parallel to the intensity direction. The limit curve of the allowable variation amount is also known in advance, and the time until the characteristic variation amount curve becomes the allowable variation amount curve can also be predicted. The life prediction unit 67 calculates the remaining time from the predicted time to the replacement time, and displays the calculated remaining time on a display unit such as a display.

  The current adjustment unit 68 receives the current intensity characteristic measured from the current intensity characteristic generation unit 61, and adjusts the power supply 44 based on the current intensity characteristic. The current adjusting unit 68 performs adjustment when the characteristic fluctuation amount does not exceed the allowable fluctuation amount. When the characteristic fluctuation amount exceeds the allowable fluctuation amount, the laser light source 41 is replaced without adjusting the current. Do.

  As described above, the current intensity characteristic of the laser light source 41 gradually deteriorates depending on the degree of use. When the current intensity characteristic is deteriorated, the organic EL mask 2 cannot be irradiated with the laser light L having a desired intensity even though a predetermined current is supplied. The desired intensity here is the intensity (set intensity) set to the laser beam L for peeling off the organic material. Even if the laser beam L is irradiated at an intensity lower than the set intensity, the organic EL mask 2 is applied. The adhering organic material cannot be sufficiently peeled, and the degree of cleaning decreases. In this case, the laser beam L can have a set intensity by adjusting the intensity to increase the current supplied to the laser beam L. If the current intensity characteristic fluctuates and the intensity of the laser beam L becomes higher than the supplied current, the intensity of the laser beam L is reduced by reducing the current supplied to the laser beam L. Try to make adjustments.

  A current intensity characteristic is input to the current adjustment unit 68, and the current amount necessary for setting the laser light L to the set intensity can be recognized based on the current intensity characteristic. 5 shows an actually measured current intensity characteristic. However, it is possible to obtain an amount of current necessary for adjusting the changed intensity based on the curve of the current intensity characteristic. When it is desired to increase the intensity of the laser beam L, adjustment is performed to increase the amount of current, and when it is desired to decrease the intensity, adjustment is performed to decrease the amount of current.

  The timing control unit 69 is connected to the mask detection sensor 34 and the unit moving unit 46, and performs movement control of the unit moving unit 46 at the timing when the mask detection sensor 34 detects the organic EL mask 2. As described above, the unit moving unit 46 moves the entire laser unit 4. At this time, the unit moving unit 46 moves between a cleaning position (a position where the organic EL mask 2 is subjected to laser cleaning) and a measurement position (a position where the intensity measuring unit 5 is irradiated with the laser light L). The laser unit 4 is moved.

  Next, the operation will be described with reference to the flowchart of FIG. First, in order to obtain ideal characteristics, current intensity characteristics are measured (initial measurement) when an unused laser light source 41 is used for the first time (step S1). At this time, the current supplied from the power supply 44 is changed at minute intervals, and the intensity measuring unit 5 measures the intensity of the laser light L corresponding to the current changed at each minute interval. Thereby, the ideal characteristic as shown by the solid line in FIG. 5 is generated (step S2). This ideal characteristic is a current intensity characteristic generated at the first timing and does not vary. The ideal characteristic is measured by setting the current change amount to a short width (high resolution) and changing the current over a wide range (measuring a wide range of current).

  The above operations are performed initially, and the following operations are performed when the organic EL mask cleaning device is operated. First, the organic EL mask 2 used in a vacuum vapor deposition tank (not shown) is carried into the cleaning stage 3 (step S3). At this time, the organic material is attached to the organic EL mask 2 in the form of a film. The organic EL mask 2 taken out from the vacuum vapor deposition tank is carried into the cleaning stage 3 through a transfer path 33 by robot means (not shown). Since the organic EL mask 2 passes through the transport path 33, the mask detection sensor 34 detects the passage of the organic EL mask 2. Thereby, the carry-in of the organic EL mask 2 is detected.

  When the mask detection sensor 34 detects the organic EL mask 2, the timing control unit 69 controls the unit moving unit 46 to move the laser unit 4 from the measurement position to the cleaning position. As a result, laser cleaning of the organic EL mask 2 becomes possible, the laser light L is oscillated from the laser light source 41, and scanning of the laser light L with respect to the organic EL mask 2 is started (step S4). Thereby, laser cleaning is performed.

  Here, laser cleaning performed by scanning the organic EL mask 2 with the laser light L will be described. Although not shown, a condensing lens is provided on the optical path of the laser light L from the laser light source 41 to the organic EL mask 2, and the laser light L is focused on the organic EL mask 2 by this condensing lens. tie. The organic EL mask 2 is a metal material (for example, nickel alloy), and the focused laser beam L is absorbed by the organic EL mask 2 and the temperature of the absorbed portion is rapidly increased. The region where the laser beam L is focused becomes a very narrow spot, and this spot and the region in the vicinity thereof are instantaneously heated to cause thermal expansion. On the other hand, since the organic material attached to the organic EL mask 2 hardly causes thermal expansion, a peeling force acts on the organic material due to a thermal expansion difference from the thermal expansion of the organic EL mask 2. Thereby, peeling force acts between the layer of the organic EL mask 2 and the layer of the organic material, and the organic material is peeled from the organic EL mask 2.

  For this purpose, the laser light L oscillated from the laser light source 41 is reflected by the galvanometer mirror 42 and applied to the organic EL mask 2. Since the galvanometer mirror 42 vibrates slightly, the irradiation position of the laser beam L changes at high speed. At this time, the laser beam L is scanned in one direction to form one scanning line, and the scanning line is finely shifted in a direction orthogonal to the scanning direction, thereby performing laser cleaning of the surface. Then, by setting this surface as a region to be cleaned of the organic EL mask 2, the laser cleaning of the organic EL mask 2 is completed. The region may be set on the entire surface of the organic EL mask 2 or may be set on a partial region.

  Then, after the laser cleaning of one organic EL mask 2 is completed, the oscillation of the laser light L from the laser light source 41 is stopped, and the organic EL mask 2 is unloaded from the cleaning stage 3 (step S5). When carrying out the organic EL mask 2, the robot means takes out the organic EL mask 2 from the cleaning stage 3 and carries it out through the transport path 33. When the mask detection sensor 34 detects when passing through the transport path 33, the carry-out of the organic EL mask 2 is recognized. Note that the mask detection sensor 34 detects carry-in and carry-out, and whether it is carry-in or carry-out can be performed based on, for example, the number of times (odd number and even number).

  After the organic EL mask 2 is carried out, a new organic EL mask 2 (organic EL mask 2 to which an organic material is attached) is carried in and scanning of the laser light is performed again. The intensity of the laser beam L is measured during the carry-out / carry-in. Steps S6 to S13 shown in the flowchart of FIG. 6 are all carried in / out, that is, while the organic EL mask 2 is being replaced. In other words, carrying-in / carrying-out is a non-scanning period in which the organic EL mask 2 is not scanned with the laser light L, and thus the processing of steps S6 to S13 is performed during this non-scanning period.

  When the mask detection sensor 34 detects the carry-out of the organic EL mask 2, the timing control unit 69 controls the unit moving unit 46 to move the laser unit 4 from the cleaning position to the measurement position. The cleaning position is the position shown in FIG. 1, and the measurement position is the position shown in FIG. In the measurement position, the laser unit 4 is located above the intensity measurement unit 5, and in detail, the galvano mirror 42 is located above the intensity measurement unit 5. In this state, laser light L is oscillated from the laser light source 41 and the light receiving unit 52 of the intensity measuring unit 5 is irradiated with the laser light L reflected by the galvanometer mirror 42. The light receiving unit 52 photoelectrically converts the incident laser light L to measure the intensity of the laser light L (step S6).

  The current intensity characteristic generation unit 61 receives the intensity of the laser light L and the current supplied by the power supply 44 at this time, and generates a current intensity characteristic based on the actually measured intensity (step S7). Then, the characteristic variation calculation unit 62 calculates the characteristic variation by calculating the difference between the generated current intensity characteristic and the ideal characteristic stored in the ideal characteristic storage unit 63 (step S8). The fluctuation amount determination unit 64 compares the calculated characteristic fluctuation amount with the allowable fluctuation amount stored in the allowable fluctuation amount storage unit 65, and when the characteristic fluctuation amount exceeds the allowable fluctuation amount (step S9), the warning unit 66 is controlled to issue a warning to that effect (step S10). In this case, since the laser light source 41 has reached the end of its life, the laser light source 41 is replaced with a new one (step S11), and the process ends.

  On the other hand, when it is determined that the characteristic fluctuation amount does not exceed the allowable fluctuation amount, the characteristic fluctuation amount is output to the life prediction unit 67, and the characteristic fluctuation amount can be used based on the characteristic fluctuation amount and the allowable fluctuation amount. The remaining time is predicted (step S12), and the predicted time is displayed. And the electric current adjustment part 68 adjusts the electric current which controls and supplies the power supply 44 (step S13). The processes from steps S3 to S13 are repeated until all the substrates are completed (step S14), and the process is terminated when the laser cleaning of all the substrates is completed.

  The current intensity characteristic obtained in step S7 is an actually measured current intensity characteristic and reflects the usage of the laser light source 41. The amount of current required to obtain the set intensity set for peeling the organic material differs between the ideal characteristic and the actually measured current intensity characteristic. Since the current intensity characteristic of the laser light source 41 is deteriorated depending on the degree of use, the amount of current necessary for irradiating the laser light L having the set intensity is larger when actually measured than when it is ideal. That is, if the current amount is kept constant, the laser beam L having a lower intensity than the laser beam L having the set intensity is gradually irradiated. For this reason, the laser beam L is always given a constant set intensity by adjusting the current amount. Of course, when the actually measured intensity is higher than the set intensity, the laser beam L having the set intensity can be obtained by adjusting the current amount.

  In the generation of the current intensity characteristics in step S7, the current range (measurement range) when measuring may be the same as the measurement range when obtaining the ideal characteristics, but the measurement range may be narrow. The measurement of the current intensity characteristic is only for recognizing the amount of current necessary for obtaining the laser beam L having the set intensity, and it is not necessary to generate a characteristic in a range greatly deviating from the set intensity. That is, the current intensity characteristic may be generated by limiting the set intensity as a target value to a part of the vicinity thereof. In FIG. 5, the current for obtaining the set intensity P is A1, and the measurement range is limited to a partial range (A2 to A3) centering on A1.

  In the series of processing from step S6 to step S13, it takes time to measure the intensity in step S6, and the current intensity characteristic is obtained by repeating this. Therefore, the time required for the processing can be shortened by measuring the measurement range to some extent. Since this process must be performed while the organic EL mask 2 is being carried in and out, that is, while the organic EL mask 2 is being replaced, by shortening the processing time, the process can be performed within the replacement time. The process can be terminated.

  Further, the process of step S7 can be omitted. In this case, only one intensity measurement is performed. Since the intensity measurement is performed only once, the intensity for a specific current value can be obtained, and the relationship in the curve as shown in FIG. 5 cannot be obtained. However, the ideal characteristic is obtained in advance, and it is possible to recognize the amount of current to be adjusted based on this ideal characteristic.

  As described above, the curve of the current intensity characteristic when it fluctuates according to the usage rate of the laser light source 41 is a curve that is almost moved in the current direction. Therefore, based on the difference between the actually measured intensity and the intensity of the ideal characteristic (ideal intensity), the actual current intensity characteristic (curve) can be predicted, and the current adjustment amount can be determined based on this. . In this case, since the number of measurements is only once, the processing time can be greatly shortened.

  As described above, since the laser beam L is measured during the exchange time for loading and unloading the organic EL mask 2, one of the laser beams L is scanned when the laser beam L is scanned (that is, during laser cleaning). The part is not taken out and measured. Thus, a part of the laser beam L is not lost during scanning, and it is not necessary to provide a dedicated optical system for extracting a part of the laser beam for measurement. In addition, all of the laser light L oscillated from the laser light source 41 is incident on the intensity measuring unit 5 to perform measurement, and the intensity of the laser light L itself actually irradiated on the organic EL mask 2 can be measured. Thereby, it is possible to measure with high accuracy. And since the intensity | strength measurement of the laser beam L is performed during replacement | exchange of the organic EL mask 2, and the intensity | strength measurement is performed within replacement | exchange time, the processing time as a whole becomes long. Absent.

  As described above, when the present invention is compared with APC, there is a reason that the present invention is more suitable for an organic EL mask cleaning device than APC, in addition to the problem of light loss and optical system. The reason for this will be described with reference to FIG.

  As described above, the laser light L oscillated from the laser light source 41 is a pulse laser. Since the laser light L is scanned so as to be focused on the surface of the organic EL mask 2, the peeled area is an extremely limited area. A scanning line in one direction (X direction) is formed by continuing this region (which is a circular region). At this time, the scanning speed of the scanning line must be constant. This is because when the scanning speed changes, the intervals between the regions become non-uniform, and the degree of cleaning varies depending on the part.

  Therefore, as shown in FIG. 8, the laser beam L is scanned not only in the mask area MA but also in the mask outside area MB. This is because the laser beam L must be scanned at a constant speed from the end to the end of the organic EL mask 2, so that the area outside the mask MB deviated from the organic EL mask 2 is accelerated by the laser beam L. This is because it must be provided as an area for deceleration. That is, the non-mask area MB is an acceleration / deceleration area.

  The outside mask area MB becomes the cleaning stage 3 on which the organic EL mask 2 is set. The cleaning stage 3 is provided with various mechanisms, and it is necessary to prevent the laser beam L from being irradiated unnecessarily. In particular, when the laser beam L is scanned at a high speed, the acceleration / deceleration region is also required in a wide range, and the influence on the cleaning stage 3 is increased.

  Therefore, when the laser light L is oscillated from the laser light source 41, the laser light L is oscillated only in the in-mask region MA, and the laser light L is not oscillated in the non-mask region MB. For this purpose, the laser light source 41 is provided with a shutter mechanism to switch the laser light L on and off. That is, the shutter mechanism is switched so that the laser beam L is shielded only when the non-mask area MB is scanned.

  APC is based on the premise that the laser beam L is always detected. When the laser beam L is switched on and off, accurate intensity detection cannot be performed. In particular, in the case of a pulse laser, since the laser beam L synchronized with the pulse is irradiated, there may be a difference between the on / off switching timing and the detection timing by the shutter mechanism. For this reason, intensity detection cannot be performed accurately. Therefore, APC is not suitable for laser cleaning.

  In the present invention, the intensity of the laser beam L is measured when the organic EL mask 2 is replaced. For this reason, even if the on-off area MB and the off-mask area MB are switched on and off, the intensity measurement is not performed during the scanning of the laser light L, so there is no influence by the on / off switching. . Also from this point, the present invention is advantageous as compared with APC.

DESCRIPTION OF SYMBOLS 1 Organic EL mask cleaning apparatus 2 Organic EL mask 3 Cleaning stage 4 Laser unit 5 Intensity measuring part 34 Mask detection sensor 41 Laser light source 42 Galvano mirror 44 Power supply 45 Laser control part 46 Unit moving part 52 Light receiving part 61 Current intensity characteristic generation Unit 62 characteristic variation calculation unit 63 ideal characteristic storage unit 64 variation variation determination unit 65 allowable variation storage unit 66 warning unit 67 life prediction unit 68 current adjustment unit 69 timing control unit

Claims (7)

An organic EL mask cleaning device that performs laser cleaning to scan a laser beam and remove an organic material adhering to the organic EL mask.
A laser light source for oscillating the laser light;
A power supply for supplying a current for causing the laser light source to oscillate the laser light;
An intensity measuring unit for measuring the intensity of laser light emitted from the laser light source;
The intensity measurement unit measures the intensity of the laser beam at the timing of replacing the organic EL mask, and the power is supplied so that the intensity is set to peel off the organic material based on the measured intensity. A laser controller for adjusting the current to be
An organic EL mask cleaning device comprising: A mask detection sensor that detects the organic EL mask in a transport path of the organic EL mask of a cleaning stage that performs the laser cleaning;
The organic EL mask cleaning apparatus according to claim 1, wherein the timing control unit causes the intensity measurement unit to perform intensity measurement at a timing detected by the mask detection sensor. The laser controller is
The apparatus according to claim 1, further comprising a warning unit that warns that a difference between the intensity of the laser beam measured by the intensity measurement unit and the set intensity exceeds an allowable error. The organic EL mask cleaning device according to 1. The laser controller is
A plurality of relationships between the current supplied by the power source and the intensity measured by the intensity measuring unit are sampled to generate a current intensity characteristic. Based on the difference between the current intensity characteristic and the ideal current intensity characteristic, the laser The organic EL mask cleaning device according to claim 1, further comprising a life prediction unit that predicts a replacement time of the light source.   An organic EL display manufacturing apparatus comprising the organic EL mask cleaning apparatus according to claim 1.   An organic EL display manufactured by the apparatus for manufacturing an organic EL display according to claim 5. An organic EL mask cleaning method for performing laser cleaning to scan a laser beam and remove an organic material attached to the organic EL mask.
The intensity of the laser beam is measured at the timing of exchanging the organic EL mask, and the laser beam is supplied to oscillate so that the intensity is set to peel off the organic material based on the measured intensity. An organic EL mask cleaning method comprising adjusting an electric current.

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