JP2014067671A - Organic el panel manufacturing device and organic el panel manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser transfer method or a transfer device which does not cause the occurrence of black spot defect caused by, during a laser transfer process, foreign matter contamination or deterioration in element light-emission characteristics associated with temperature rise, or which enables transfer of an organic layer on a donor substrate to a circuit board at high speed and at high stability.SOLUTION: An organic EL panel manufacturing method of the present embodiment comprises: opposing a circuit board on which a lower electrode is formed with respect to a donor substrate on which an organic EL film is laminated on one principal surface with a constant distance with the donor substrate being kept to convert an oscillation laser beams to a plurality of rectangular laser beams having a rectangular uniform intensity distribution; arranging the plurality of rectangular laser beams in series and at regular intervals to irradiate the plurality of rectangular laser beams on the donor substrate in a predetermined region of the other principal surface at predetermined times in an overlapping manner at prescribed time intervals and more; and peeling off the organic EL film from the donor substrate to transfer the organic EL film on the circuit board opposite the donor substrate.

Description

  The present invention relates to an organic EL panel manufacturing apparatus and an organic EL panel manufacturing method, and more particularly to a technique for stably and stably forming an organic EL light emitting layer.

  An organic EL (Electroluminescence) element has excellent performance such as self-luminance, high-speed response, and a wide viewing angle. Due to these excellent performances, in recent years, organic EL elements have been developed as devices for display panels that express high-quality moving images. The organic EL element has a multilayer structure in which an organic hole transport layer, an organic electron transport layer, an organic light emitting layer, and the like are laminated between a cathode and an anode.

  A mask vapor deposition method is generally used as a method for forming a thin organic EL film to be a light emitting layer or the like of an organic EL display device. The mask vapor deposition method is a method in which a substrate is covered with a vapor deposition mask in which openings are formed in a pattern, and an organic substance is deposited through the openings to form an organic EL film on the substrate. Since the organic EL display device has high pixel definition, the opening of the vapor deposition mask is very small. In the mask vapor deposition method, the organic EL film is deposited on the mask covering the substrate, and the opening diameter changes. Therefore, periodic replacement, cleaning, or maintenance of the vapor deposition mask is necessary, resulting in the problem of reduced productivity. Have.

  Also, in the mask vapor deposition method, the mask itself undergoes thermal expansion upon receiving heat radiation from the evaporation source, so that the alignment accuracy between the mask opening position in the peripheral part of the mother substrate and the predetermined vapor deposition address on the circuit board can be ensured. In other words, it was a factor that hindered the response to the increase in the size of the mother board and the higher definition of the panel.

  In order to solve these problems, an organic EL layer is sublimated or peeled off by bringing a donor substrate on which an organic layer has been previously deposited into close contact with or close to an element substrate on which an element is formed and irradiating the donor substrate with a laser beam. A maskless transfer system for transferring to an element substrate has been proposed.

  As a method of irradiating a laser onto a donor substrate on which an organic layer has been formed in advance and transferring the organic layer to a desired region on a circuit board, Patent Document 1 (Japanese Patent Laid-Open No. 2002-302759) discloses a light emitting material on the entire surface of a glass substrate. A technique is disclosed in which a light emitting material is sublimated by irradiating a donor substrate coated with a substrate with a laser, and an organic EL layer is formed on a device substrate placed oppositely. Patent Document 2 (Japanese Patent Laid-Open No. 2006-216563) discloses a method in which a donor film coated with a light emitting material is brought into close contact with a device substrate, and a light emitting layer is thermally transferred to a predetermined place. In Patent Document 3 (Japanese Patent Laid-Open No. 2010-40380), an organic layer is peeled off from a donor substrate using a shock wave generated on the surface of the donor substrate by irradiating the donor substrate with laser light, and a predetermined circuit board is formed. A laser transfer method is disclosed in which an organic EL panel is formed by adhering to the above portion.

JP 2002-302759 A JP 2006-216563 A JP 2010-40380

  Patent Document 1 discloses a technique in which a light emitting material is sublimated by irradiating a donor substrate having a light emitting material coated on the entire surface of a glass substrate, and an organic EL layer is formed on a device substrate placed oppositely. ing. However, since the laser energy is converted into heat and heated to a temperature at which the light emitting material is sufficiently sublimated, there is a problem that impurities are likely to be mixed due to a temperature increase in the transfer atmosphere, and the organic EL element characteristics are likely to deteriorate.

  Patent Document 2 discloses a method in which a donor film coated with a light emitting material is brought into close contact with a device substrate, and a light emitting layer is thermally transferred to a predetermined place. However, in order to bring the device substrate and the donor film into close contact with each other, if a foreign substance exists, pressure is applied in a state where the foreign substance is sandwiched between them, so that there is a problem that black spot defects due to the foreign substance increase when the device is formed.

  In Patent Document 3, a donor substrate in which an organic EL layer and a laser light absorption layer are laminated is irradiated with laser light to generate a shock wave on the surface of the donor substrate, and the organic layer is peeled off from the donor substrate by the shock wave. And a laser transfer method for forming an organic EL panel by transferring a thin film piece to a predetermined portion of a circuit board. However, there is no disclosure of a specific laser irradiation method for realizing organic layer peeling transfer with high efficiency and high stability.

  A first object of the present invention is to solve the above-described problems of the prior art, and to perform a laser transfer method that does not cause a deterioration in element light emission characteristics due to a temperature rise or a black spot defect due to contamination by foreign matter during the laser transfer process. It is to provide a transfer device.

  A second object of the present invention is to provide a laser transfer method or transfer apparatus that can transfer an organic layer on a donor substrate to a circuit board at high speed and with high stability.

In order to solve the above problems, the present invention has at least the following features.
The present invention includes a stage on which a donor substrate having an organic layer formed on one main surface, a circuit board facing the one main surface with a certain space therebetween, a laser oscillator that oscillates laser light, and the laser Laser light shaping means for converting light into a rectangular uniform intensity distribution; laser light distribution means for obtaining two or more laser lights in which the laser lights of the uniform intensity distribution are distributed in series and at equal intervals; A projection lens for reducing and projecting two or more laser beams onto the other main surface of the donor substrate, and the laser beams distributed in series and at equal intervals and the stage are moved relatively at a constant speed in the series direction. And a control means for superimposing and irradiating the same location on the other main surface of the donor substrate with the constant speed movement.

  In the present invention, a first electrode made of a conductive thin film is formed on a circuit board, an organic EL layer including at least a light emitting layer is formed on the first electrode, and the organic EL layer is formed on the organic EL layer. A method of manufacturing an organic EL panel for forming a second electrode, wherein the circuit substrate on which a lower electrode is formed is spaced apart from the donor substrate with respect to a donor substrate having an organic EL film laminated on one main surface. Maintaining the one main surface, and converting the oscillated laser beam into a plurality of rectangular laser beams having a rectangular uniform intensity distribution, arranging the plurality of rectangular laser beams in series and at equal intervals, Irradiating a predetermined region of the other main surface of the donor substrate with a predetermined number of times over a predetermined time, peeling off the organic EL film from the donor substrate, and transferring it onto the facing circuit substrate And

  According to the present invention, it is possible to provide a laser transfer method and a transfer apparatus that do not cause deterioration of element light emission characteristics due to temperature rise or black spot defects due to contamination by foreign matters during the laser transfer process.

  Further, according to the present invention, it is possible to provide a laser transfer method and a transfer apparatus that can transfer an organic layer on a donor substrate to a circuit substrate at high speed and with high stability.

It is a figure which shows the structure of the laser transfer apparatus concerning the 1st Example of this invention. It is a figure which shows the structure of the diffractive optical element employable for the laser transfer apparatus concerning the Example of this invention, and the uniform intensity distribution of the desired shape formed. It is a figure which shows the structure of the laser transfer apparatus concerning the 2nd Example of this invention. It is a figure which shows the other structure of the diffractive optical element employable for the laser transfer apparatus concerning the Example of this invention, and the uniform intensity distribution of the desired shape formed. It is a figure explaining one Example of the laser transfer method concerning this invention. It is a figure explaining the appropriate condition range of the laser transfer method concerning this invention. It is a figure which shows the structure of the laser transfer apparatus concerning the 3rd Example of this invention. It is process drawing which showed an example of the organic electroluminescent display production process to which this invention is applied. It is sectional drawing which shows the structure of the completed organic EL element.

  Embodiments of the present invention will be described below in detail based on examples. The present invention is not limited to the following examples.

Example 1
FIG. 1 is a diagram showing a configuration of a laser transfer apparatus 100 as a first embodiment suitable for carrying out the method for manufacturing an organic EL panel of the present invention. The laser transfer apparatus 100 irradiates a donor substrate 312 with a laser oscillator 1 that is an LD excitation pulse solid laser, a pre-processing unit, a beam diameter adjusting unit that adjusts a beam diameter, and laser light processed by the beam diameter adjusting unit. An irradiating process section, a transfer section for transferring the thin organic EL film from the donor substrate 312 to the circuit board 310, and an overall control section (not shown).

  The preprocessing unit includes an ND filter 2 for adjusting the output of the pulsed laser light 3 oscillated from the laser oscillator 1, an optical shutter 4 composed of a Pockels cell and a polarization beam splitter for cutting out the laser light at a desired timing. With.

  The beam diameter adjusting unit includes a beam expander 5 for adjusting the beam diameter of the laser light from the optical shutter 4, a laser light branching mechanism 6 for branching a part of the laser light, and a space of the branched laser light. A beam profiler 7 for measuring an intensity distribution, a signal processing unit 8 for processing a spatial intensity distribution signal measured by the beam profiler 7 to extract a beam diameter and comparing it with a reference value, and a beam expander 5 based on the processing result And a drive driver 9 for driving.

  The irradiation processing unit is provided with a drive mechanism (not shown), optical axis adjusting mirrors 10 and 11 for adjusting the optical axis of the branched laser light, and the laser light to an intensity distribution having a desired shape on the imaging plane. And a projection lens 15 for reducing and projecting the shaped optical image on the irradiation surface (on the sample surface).

The transfer unit includes a stage 17 on which the circuit board and the donor substrate 16 are mounted, a beam profiler 18 for measuring the spatial intensity distribution of laser light on the stage, and a spatial intensity distribution and a reference intensity distribution measured by the profiler 18. And a signal processing device 19 for comparison.
As shown in FIG. 5 to be described later, the donor substrate and the circuit board 16 in which the organic EL thin film 304 is formed with a uniform film thickness on one main surface side are the side on which the organic EL thin film 304 is formed on the donor substrate 312. Is held on the stage 17 in the vacuum chamber 50 so that the surface on which the circuit on the circuit board 310 is formed faces each other. A beam profiler 18 is provided inside the vacuum chamber 50.

A laser oscillator 1 that generates pulsed laser light having an ultraviolet or visible wavelength is used. In particular, the second harmonic of a laser diode-pumped YVO ₄ laser or a laser diode-pumped Nd: YAG laser because of its output size and output stability. A wave (wavelength: 532 nm) is appropriate. However, without being limited to this, it is possible to use an argon laser, an excimer laser, a third or fourth harmonic of a YVO ₄ or YAG laser, a plurality of semiconductor lasers coupled by a fiber, and the like.

  In addition to the Pockels cell, an AO (acousto-optic) modulator can be used as a component constituting the optical shutter 4. However, in general, the AO modulator has the disadvantages that the driving frequency is lower and the diffraction efficiency is slightly lower, such as 70 to 80%, compared to the Pockels cell, but it can be used. In this way, by using an optical shutter such as the Pockels cell 4 or the AO modulator, pulses can be cut out and irradiated at a desired timing from the pulse train (pulse train) of the laser oscillator 1.

  The laser light 3 applied to the donor substrate 312 is shaped into rectangular laser light having at least two uniform intensity distributions by the laser light shaping means 12 in order to convert it into laser light suitable for laser transfer. Since the output beam from the gas laser oscillator or the solid laser oscillator is usually circular and has a Gaussian function type energy distribution, it cannot be applied to the laser transfer of the present invention as it is. If the output of the oscillator is sufficiently large, it is possible to obtain an arbitrary shape with a substantially uniform energy distribution by sufficiently widening the beam diameter and cutting out from the relatively uniform portion of the central portion to the required shape. The peripheral part is thrown away, and most of the energy is wasted. Further, when the transfer process for each pixel pitch is repeated with a single laser beam over the entire surface of the large substrate, there is a problem that the throughput is significantly reduced. In order to solve these disadvantages and convert a single laser pulse having a Gaussian function type distribution into laser beams having a plurality of uniform distributions, laser beam shaping means and laser beam distribution (branching) means A laser beam shaping / branching unit 12 having a function is used.

  A diffractive optical element is a typical example of means for shaping a single laser beam having a non-uniform intensity distribution of a Gaussian function type into a plurality of uniform intensity distributions. The laser beam shaping / branching means 12 used in the present invention. However, the present invention is not limited to this, and any means may be used as long as the laser light is uniform in a rectangular shape or can realize an energy distribution suitable for laser transfer. Further, as means for increasing the power density while maintaining the spatial intensity distribution of the laser light 3 shaped and branched by the laser light shaping / branching means 12 and narrowing it to a desired pitch, the laser light shaping means 12 and the donor substrate 312 are provided. An optical image may be reduced and projected by inserting a reduction projection lens 15 (not shown) therebetween.

Here, the function of the diffractive optical element used for the laser transfer of the present invention will be described in detail. FIG. 2 is a diagram for explaining a function of converting laser light having a Gaussian function type intensity distribution into a plurality of (four in FIG. 2) uniform intensity distributions by the diffractive optical element 20.
The diffractive optical element 20 creates a step pattern having a wavelength of visible light on a transparent flat substrate by a photolithography process, and causes light to pass through the step pattern, thereby generating an optical path length for laser light passing through each pattern. An optical element that freely controls the wavefront and phase of a laser beam and forms a laser pattern with an arbitrary intensity distribution and shape on an arbitrary imaging plane with an arbitrary number of divisions. The diffractive optical element 20 can set the extraction efficiency of the 0th-order diffracted light as very high as 90% or more, and is used for a shaping optical system of a laser having a short coherence length (low coherence) such as excimer laser light. Compared with a multi-lens array method (fly-eye method) or the like, it is an element that can efficiently extract laser beam energy. Further, since the diffractive optical element 20 shapes the laser light by utilizing light diffraction, the coherent length of a solid laser or the like is long (high coherence), and the conventional multi-lens array method, fly-eye method, or the like is used. There is an advantage that it can be applied to a laser beam shaping optical system which is difficult to be shaped by the laser beam shaping technique. Further, since the diffractive optical element 20 performs laser beam shaping with a single element, it is more advantageous than the above two methods in terms of ease of maintenance of the optical system.

  In the diffractive optical element 20 shown in FIG. 2, a uniform intensity distribution 25 having a desired shape is formed on the image plane 24 when the laser beam 3 having a Gaussian function type intensity distribution 21 is incident on the center of the element. Designed. The incident laser beam 3 has a Gaussian function type intensity distribution 21, and the center position and traveling direction of the laser beam coincide with the optical axis 23. The optical axis 23 in this case means an axis that passes through the center position of the diffractive optical element 20 and extends in a direction perpendicular to the surface of the diffractive optical element. That is, the center of the diffractive optical element 20 and the center of the laser beam 3 coincide. When the laser beam 21 is incident on the diffractive optical element 20 in such a state, the shaped laser beam intensity distribution 25 on the imaging surface 24 is converted into a uniform intensity distribution suitable for the transfer of the organic material.

(Example 2)
FIG. 3 is a diagram showing a second embodiment of a laser transfer apparatus 200 having other laser beam branching means when an oscillator having sufficiently large energy is used. FIG. 4 is a diagram showing another laser beam branching means. The diffractive optical element 30 shown in FIG. 4A makes a laser beam 3 having a Gaussian function type intensity distribution 31 incident thereon, and forms a laser beam having a uniform intensity distribution 35 on a certain imaging plane 34. It is a shaping tool. A mask 13 which is a laser beam branching (distributing) means in which an arbitrary aperture pattern, for example, a regular rectangular aperture pattern is formed, is inserted on the imaging surface 34 of the diffractive optical element 30, and the aperture 13 K of the mask 13 is formed. A plurality of laser beams transmitted and distributed are obtained. Further, as shown in FIG. 3, an image may be formed on the donor substrate via a relay lens 14 and a projection lens for converting a plurality of laser beams into parallel light.

  According to the second embodiment, as shown in FIG. 4B, if the opening pattern 13K of the mask 13 is set in a matrix, a plurality of laser beams are arranged in the laser scanning direction and the direction orthogonal to the laser scanning direction. In addition, since a plurality of rows can be irradiated on the donor substrate 312 in a superimposed manner, a significant improvement in throughput can be expected.

  As shown in FIG. 5 to be described later, the donor substrate 312 and the circuit substrate 310 in which the organic EL film is formed with a uniform thickness on one main surface side are the surfaces on the side where the organic EL film on the donor substrate is formed. Is held on the stage 17 in the vacuum chamber 50 so that the surface of the circuit board on which the circuit is formed faces each other. In the first and second embodiments, the donor substrate 312, the circuit substrate 310, and the stage 17 are held in the vacuum chamber 50. In addition, after sealing the peripheral portion of the substrate disposed oppositely with a clamping frame or the like, the space between the donor substrate 312 and the circuit substrate 310 is dried by a dry pump, a turbo molecular pump, or a cryopump (all not shown). You may employ | adopt the form which hold | maintains a vacuum.

  The donor substrate 312 is preferably a metal plate made of Ti, Ni, Cu, Fe, Au, Cr, Mo, W, or an alloy containing these, and the thickness of the donor substrate is about 5 to 10 microns. Is preferred. On the surface of the donor substrate 312 facing the circuit substrate 310, an organic EL film to be transferred to the circuit substrate in advance with a uniform film thickness is formed by vacuum deposition or the like. The distance between the donor substrate and the circuit board for film deposition that are placed opposite to each other must be kept constant over the entire surface of the substrate. For this purpose, either the periphery of the pixel region on the circuit board or the donor substrate is used. On one side, it is preferable that a projection or a spacer formed by a photolithography process is provided (not shown). The thickness of the protrusion or spacer is several μm to several hundred μm, preferably about 80 to 100 μm, and these are formed by a photolithography process. The spacers are arranged in four directions so as to surround each pixel or a plurality of pixel regions (so as not to overlap the pixel regions), but it is preferable that a gap is provided between spacer frames surrounding the four sides. Due to this gap, when the gap between the donor substrate and the circuit board is kept opposite to each other via the spacer, the regions partitioned by the spacer are all held at a constant pressure. That is, the protrusions and spacers can keep a constant distance between the surface of the donor substrate on which the organic EL film is formed and the circuit board.

Next, a method for manufacturing an organic EL panel applicable to each embodiment of the present invention will be described with reference to the drawings.
FIGS. 5A to 5D are diagrams showing an example of a process of transferring the organic EL film 304 onto the circuit board 310 using the laser transfer method of the present invention. FIG. 5 will be described on behalf of one row in the case of transferring in a matrix. As shown in FIG. 5A, the laser beam 3 is diffracted by the laser beam shaping / means 12 shown in FIG. 2 on a donor substrate 312 in which an organic EL film 304 having a uniform film thickness is previously formed on a metal foil. The optical element 20 branches into four laser beams having a uniform intensity distribution. Then, the laser beam branched in the direction of the arrow is scanned relative to the donor substrate 312, and the desired region is sequentially moved from FIG. 5A to FIG. 5D and irradiated. At this time, the laser scanning speed is set so that the four branched laser beams are superimposed on the relative coordinates 0 to X7 (transfer region 320 to transfer region 327) to which the organic EL film 304 is transferred at regular intervals. adjust.

  Alternatively, at this time, in order to increase the degree of freedom in adjusting the laser irradiation timing, the pulse train of a laser oscillator that oscillates at a high frequency is thinned out using an optical shutter 4 (see FIG. 1) such as an EO modulator or an AO modulator. By performing, it may be adjusted so that the laser is superimposed on the desired region.

  Here, a generation mechanism of a thermoelastic wave by laser beam irradiation on the donor substrate 312 and a peeling mechanism of the organic EL film 304 will be described. The metal foil irradiated with the laser absorbs laser light energy at the extreme surface. As a result, only the lattice near the pole surface locally expands thermally. The lattice in the vicinity of the thermally expanded pole surface compresses the lattice in the depth direction, and this compressive strain propagates through the lattice at the speed of sound. That is, an elastic wave is generated. On the other hand, the free surface (laser irradiation surface) expands in such a way as to release the strain accumulated in the lattice. When the compression wave propagating in the depth direction reaches the back surface, the free surface on the back surface is now undulated. A force to restore the original shape acts on the undulating surface, and the elastic wave is reflected and propagated in the opposite direction.

  In this way, thermoelastic waves reciprocate in the metal foil, and a resonance state can be obtained. The organic EL film 304 is mechanically peeled off from the metal foil when the resonance state of the metal foil is received for a certain period of time or longer, and is transferred to the opposite circuit board 310.

  At this time, there is an appropriate range for the intensity of the laser beam that induces an elastic wave suitable for mechanical peeling of the organic EL film 304. FIG. 6 is a schematic diagram showing an appropriate range of the laser peeling transfer process of the organic film. The horizontal axis and the vertical axis respectively correspond to the number of times of laser superposition and the energy density of the laser. It is considered that the following two phenomena occur when one main surface is irradiated with laser light having an intensity of an appropriate range or more. One is a phenomenon in which the heat of the heated polar surface of one main surface is conducted and the organic film temperature of the multi-main surface rises, and the other is a thermoelastic wave with a large amplitude (energy) on the other main surface. Is a phenomenon in which adiabatic compression due to wave propagation occurs when passing through the organic EL film, and the temperature in the film rises. Due to these combined factors, the temperature in the film is unnecessarily increased, and a problem of damaging the organic film is likely to occur. That is, the function as the organic EL film is lost.

  On the other hand, when the laser beam below the appropriate range is irradiated, the amplitude (energy) of the induced thermoelastic wave is not large, so it attenuates before the next laser pulse is irradiated, and mechanical peeling occurs. A sufficient resonance state cannot be obtained. That is, an appropriate resonance state suitable for peeling can be continuously obtained only when a laser pulse with an appropriate intensity is superimposed and irradiated an appropriate number of times.

  The transfer region 320 on the donor substrate 312 shown in FIG. 5A corresponds to a region where the superimposed irradiation of the four branched laser beams has been completed. By four times of laser irradiation, a thermoelastic wave having a desired amplitude intensity is continuously induced for a predetermined time or more, and the organic EL film 304 on the back surface is transferred to the circuit substrate 310 (relative coordinate 0) as a peeling piece 305. The transfer region 321 (relative coordinate X1) is irradiated with laser three times, the transfer region 322 (relative coordinate X2) is irradiated twice, and the transfer region 323 (relative coordinate X3) is irradiated once. The thermoelastic wave traveling in the depth direction of the irradiated region is induced, but the organic film is not peeled and transferred. A region 330 (relative coordinates X4 to X7) surrounded by a broken line corresponds to a laser non-irradiated region.

  FIG. 5B shows a state after a certain time has elapsed. The laser beam 3 and the optical element 20 move relative to the donor substrate 312 facing the circuit substrate 310, and a fourth laser irradiation is performed on the transfer region 321 (relative coordinate X1). As a result, the conditions for peeling the organic film in the transfer region 321 are satisfied, and the organic EL film 304 is peeled and transferred to the coordinate X1 on the circuit board 310. At the same time, the third laser irradiation is performed on the transfer region 322 (relative coordinate X2), the second laser irradiation is performed on the transfer region 323 (relative coordinate X3), and the first laser irradiation is performed on the transfer region 324 (relative coordinate X4).

  Further, FIG. 5C shows a state after a certain time has elapsed. The laser beam 3 and the optical element 20 are further moved in the direction of the arrow relative to the donor substrate 312 facing the circuit substrate 310, and a fourth laser irradiation is performed on the transfer region 322 (relative coordinate X2). As before, the conditions for peeling the organic film in the transfer region 322 (relative coordinate X2) are satisfied, and the organic EL film 304 is peeled and transferred to the coordinate X2 on the circuit board 310. At the same time, the third laser irradiation is performed on the transfer region 323 (relative coordinate X3), the second laser irradiation is performed on the transfer region 324 (relative coordinate X4), and the first laser irradiation is performed on the transfer region 325 (relative coordinate X5).

  Further, FIG. 5 (d) shows a state after a predetermined time has elapsed. The laser beam 3 and the optical element 20 further move in the direction of the arrow relative to the donor substrate 312 facing the circuit substrate 310, and a fourth laser irradiation is performed on the transfer region 323 (relative coordinate X3). As before, the conditions for peeling the organic film in the transfer region 323 (relative coordinate X3) are satisfied, and the organic EL film 304 is peeled and transferred to the coordinate X3 on the circuit board. At the same time, the third laser irradiation is performed on the transfer region 324 (relative coordinate X4), the second laser irradiation is performed on the transfer region 325 (relative coordinate X5), and the first laser irradiation is performed on the transfer region 326 (relative coordinate X6).

  Thereafter, the laser beam is repeatedly applied to the necessary area on the circuit board at regular intervals. Thus, a stable transfer process can be realized without damaging the organic film due to an unnecessary temperature rise.

  In the transfer process described above, each transfer region is moved discretely. However, it may be moved discretely in a common divisor unit of the branched laser light and superimposed on the same transfer region a predetermined number of times. . For example, when the number of branches is 4, the common divisors are 1, 2, and 4. In the case of 2, laser irradiation is performed twice at the same position, and it is moved discretely twice for every two transfer regions. In the case of 4, laser irradiation is performed four times at the same position, and the light is discretely moved once every four transfer regions. In general, if N is the number of branches, M is the common divisor of N, P is the number of movements, and L is the number of irradiations at the same position, then P = N / M and L = N / P. Furthermore, in the above description, the predetermined number of times = the number of branches, it is also possible to set the number of branches to an integer multiple of the predetermined number of times. In that case, first, the number of branches = a predetermined number of times, irradiation is performed by the above-described method, and then the light is discretely moved according to the true number of branches.

  According to the first and second embodiments of the laser transfer apparatus described above, a plurality of laser beams having a uniform intensity distribution are distributed at regular time intervals on the other main surface on the donor substrate in which the organic EL thin film is laminated on one main surface. By superimposing irradiation while maintaining the temperature, it is possible to continuously generate a thermoelastic wave suitable for peeling the organic EL thin film in the donor substrate while suppressing damage due to the temperature rise of the organic EL thin film.

  Further, according to the first embodiment of the laser transfer apparatus described above, the laser beam is branched and arranged in series with respect to the scanning direction, so that the laser beam is superimposed on the same portion to induce a desired thermoelastic wave. In this case, a desired laser transfer process can be realized without impairing the throughput.

  Further, according to the second embodiment, the laser transfer apparatus described above distributes laser light with a mask in which an arbitrary aperture pattern, for example, a regular rectangular aperture pattern, is provided in a matrix, and superimposes the laser beam on the same location. When a desired thermoelastic wave is induced by irradiation, a desired laser transfer process can be realized without impairing throughput.

Example 3
FIG. 7 is a diagram showing a configuration of a laser transfer apparatus 300 of Example 2 suitable for carrying out the method for manufacturing an organic EL panel of the present invention.

The difference from the first embodiment of the laser transfer apparatus 200 of the third embodiment is that a plurality of laser oscillators 1 are provided in series and at equal intervals as laser light distribution means. Further, the diffractive optical element 30 shown in FIG. 4 is used as the laser beam shaping means, and laser beams are formed in series and at equal intervals. Of course, the laser light having a uniform intensity distribution in the form of a matrix may be formed by using the diffractive optical element 30 which is the laser light shaping / branching means 12 for branching the plurality of laser lights shown in FIG.
Moreover, you may provide one part or all part of the component which forms an optical system with respect to one laser beam with respect to a laser beam, respectively. Furthermore, a plurality of laser oscillators 1 may be provided in a matrix and at equal intervals.

The transfer process shown in FIG. 5 can also be used in the fourth embodiment.
Also in Example 3, the same effect as Example 1 or 2 can be produced.

  According to the first to third embodiments described above, it is possible to provide a laser transfer method and a transfer apparatus that do not cause deterioration of element light emission characteristics due to temperature rise or black spot defects due to contamination by foreign matters during the laser transfer process.

  Further, according to the first to third embodiments described above, it is possible to provide a laser transfer method and a transfer apparatus that can transfer an organic layer on a donor substrate to a circuit substrate at high speed and with high stability.

Example 4
As Example 4, the result of conducting a principle verification experiment of the laser transfer system of the present invention is shown. Alq3 (light emitting layer and electron transport layer) was formed as a transfer layer with a film thickness of 65 nm on one main surface of a 10 μm thick SUS304 donor substrate by vacuum deposition. On the other hand, an ITO (anode electrode) film having a thickness of 150 nm and an α-NPD (hole transport layer) having a film thickness of 125 nm were sequentially formed on one main surface of a glass substrate as a circuit board on the Alq3 transfer side.

Next, the donor substrate and the glass substrate are set so that the Alq3 film surface and the α-NPD film surface face each other through a spacer having a thickness of 80 μm and held in the vacuum layer, and then the window material for the vacuum layer Then, a pulse YAG laser (wavelength 532 nm, output 6 W, pulse width 10 ns, repetition frequency 20 kHz) is inserted in one direction at a speed of 0.8 m / s on the other main surface of the SUS304 donor substrate (the side where the Alq3 layer is not formed). It was pulled and irradiated. The output per laser pulse was 300 μJ, the irradiation beam diameter on the SUS304 plate was set to 190 μm, and laser irradiation was performed at an energy density of 1 J / cm ² . From the relationship between the repetition frequency of the laser and the insertion speed, a laser pulse having a spot diameter of 190 mm is sequentially performed by moving by 40 μm in one direction every 50 μs. In other words, the laser beam is superimposed on the same location on the SUS donor substrate four times.

  After one-line irradiation under such irradiation conditions, the beam spot was moved relative to the direction perpendicular to the insertion direction by 100 μm and the same insertion irradiation was performed. After repetitively moving the beam in this way and inserting and irradiating the entire surface of the substrate, 0.5 nm of LiF (electron injection layer) and Al (cathode electrode) are sequentially deposited on the transferred Alq3 film to form a glass substrate. The laminated film formation substrate was bonded and sealed.

In the organic EL light-emitting device formed by this method, light emission was confirmed over the entire transferred surface. At this time, the light emission voltage at a luminance of 100 cd / m ² was 9V. Considering light absorption of the SUS donor substrate and heat conduction in the plate thickness direction, the temperature rise on the Alq3 layer side due to laser superimposed irradiation was estimated, and the temperature was about 70 ° C. This is a temperature much lower than the Alq3 sublimation temperature.

  From this, in this system, it can be understood that the organic layer is transferred to the device substrate side by a phenomenon other than thermal sublimation. That is, it is considered that the transfer is performed by mechanical peeling by laser thermoelastic waves as described in the first embodiment. Since the organic film temperature can be suppressed to a low temperature, a stable transfer process can be realized as a film having an original function while suppressing thermal damage of the organic film.

  These studies have demonstrated that Alq3 is mechanically transferred while maintaining its molecular structure without sublimation (decomposition) by heat due to propagation of thermoelastic waves induced by pulse superposition irradiation. Realization of transfer while maintaining the molecular structure means that stable organic layer transfer can be realized without impairing device performance.

(Comparative example)
In Example 4, an organic EL device was formed in the same manner as in Example 2 except that the thickness of the SUS plate used as the donor substrate was 2 μm and the laser insertion speed was 3.2 m / s. In the case of insertion at 3.2 m / s, the movement between laser pulses corresponds to 160 μm from the relationship with the laser oscillation frequency. That is, in the irradiation of Comparative Example 2, the laser pulse is not superimposed on the same location on the SUS304 donor substrate (one pulse irradiation).

  When the light emission characteristics of the device formed under such laser irradiation conditions were examined, device light emission was not confirmed at the center of spot irradiation. When the temperature rise on the Alq3 layer side when the SUS plate thickness condition was 2 μm was estimated, the temperature was about 270 ° C. This temperature exceeds the temperature at which Alq3 sublimates, and it is presumed that thermal sublimation / decomposition of the material occurred due to the temperature rise in the film during the laser transfer process.

  The embodiment of the laser transfer apparatus and the laser transfer method using the transfer apparatus has been described above.

  Here, a manufacturing process of a display device using an organic electroluminescence (EL) element including the laser transfer process described above will be described. FIG. 8 is a flowchart showing the manufacturing process, and FIG. 9 is a cross-sectional view showing the structure of the completed organic EL element. As shown in these figures, an SiN film 402 and an SiO film 403 that function as a barrier film are thinly deposited on a glass substrate 401 by means of CVD or the like, and an amorphous silicon film or IGZO that forms a channel portion of the transistor is formed thereon. A film 404 is deposited to a thickness of about 50 nm by a CVD method, and a film quality conversion process such as laser annealing is performed as necessary. It should be emphasized that the layer structure and film thickness of the barrier film and the film thickness and film quality of the thin film constituting the transistor channel described here are merely examples, and the description does not limit the present invention. is there.

  The channel film 405 formed as described above is etched into an island shape so as to become a predetermined circuit, and after forming a gate insulating film (not shown) and a gate wiring 406, impurity diffusion by ion implantation, and impurity diffusion regions By performing activation annealing and sequentially forming the source / drain wiring 407, the interlayer insulating film 408, the passivation film 409, and the transparent electrode 410, an active matrix substrate in which the transistor circuit is arranged in the pixel portion can be formed.

  The number of transistors per pixel required for driving the organic EL element is selected from 2 to 5, and an optimum circuit configuration combining the transistors may be used. As such a circuit, a low current driving circuit formed of a CMOS circuit is recommended as an example. Details of processing techniques relating to such circuit and electrode formation are well known to those skilled in the art. It is also well known that additional steps such as ion implantation and activation annealing are necessary during the manufacturing process of the transistor circuit.

  Next, an element isolation band 411 is formed around the transparent electrode 410 on the active matrix substrate. The element isolation band 411 is required to have insulating properties, and an organic material such as polyimide may be used, or an inorganic material such as SiO 2 or SiN may be used. The film formation and pattern formation method of the element isolation band 411 is also well known to those skilled in the art.

  Next, as described above, the hole transport layer 412, the light emitting layer 413, the electron transport layer (not shown) of the organic EL material, and the cathode 414 are sequentially formed on the transparent electrode 410. At this time, a multi-layered film including an organic layer may be collectively transferred by the laser transfer method as described above. In addition, the light emitting layer 413 having different emission colors may be separately coated on a specific transparent electrode 410 by using laser transfer and mask vapor deposition. It is well known that a multicolor display can be formed thereby.

  The filler 415 is applied only to the pixel area by means such as screen printing, and the sealing plate 416 is laminated on the filler 415 to complete the sealing. A lighting test is performed on the organic EL display device thus formed. In the lighting inspection, even if defects such as black spots and white spots have occurred, those that can be corrected are corrected. Thereafter, an organic EL display device is completed through a module process of storing in a housing as necessary.

  The present invention is not only effective for a so-called low molecular type display in which the organic layer described above is formed by laser transfer and vacuum deposition, but is also effective for an organic EL display called a so-called polymer type. Furthermore, the present invention is not effective only for the production of a so-called bottom emission type organic EL in which a transparent electrode, an organic layer, and a cathode are sequentially laminated on a glass substrate as described above, and EL light emission is extracted to the glass substrate side. It is also effective for manufacturing a so-called top emission type organic EL in which a cathode, an organic layer, and a transparent electrode are sequentially laminated on a glass substrate and EL light emission is extracted to the sealing substrate side.

DESCRIPTION OF SYMBOLS 1 ... Laser oscillator 3 ... Laser light 4 ... Optical shutter 12 ... Laser beam shaping / branching means 13 ... Mask 13K ... Mask opening 14 ··· Relay lens 16 ··· Donor substrate and circuit board 17 ··· Stage 18 ··· Beam profiler 20 and 30 · Diffractive optical element 21 · · · Gaussian intensity distribution 25 and 35 · Uniform Intensity distribution, 50 ... Vacuum chamber 100, 200, 300 Laser transfer device 310 ... Circuit board 304 ... Organic EL film, 305 ... Stripping piece 312 ... Donor substrate 320-327 ... Transfer Area 330 ... Unirradiated area

Claims (15)

A stage on which a donor substrate having an organic layer formed on one main surface, and a circuit substrate opposed to the one main surface with a certain distance therebetween,
A laser oscillator that oscillates laser light;
Laser light shaping means for converting the laser light into a rectangular uniform intensity distribution;
Laser light distribution means for obtaining two or more laser beams in which the laser beams of uniform intensity distribution are distributed in series and at equal intervals, and projection for reducing and projecting the two or more laser beams onto the other main surface of the donor substrate A lens,
Moving means for moving the laser beam and the stage distributed in series and at equal intervals relatively at a constant speed in the series direction;
Control means for irradiating the donor substrate with the same velocity on the other main surface of the donor substrate in an overlapping manner,
An organic EL panel manufacturing apparatus comprising: In the organic electroluminescent panel manufacturing apparatus of Claim 1,
The organic EL panel manufacturing apparatus, wherein the laser beam distribution unit is a laser beam branching unit having a function of branching the laser beam having the uniform intensity distribution into a plurality of laser beams in series and at equal intervals In the organic electroluminescent panel manufacturing apparatus of Claim 2,
2. The organic EL panel manufacturing apparatus according to claim 1, wherein the laser beam shaping unit and the laser beam distributing unit are diffractive optical elements that generate the plurality of laser beams having the uniform intensity distribution in series and at equal intervals. In the organic electroluminescent panel manufacturing apparatus of Claim 2,
The laser beam shaping unit is a diffractive optical element that forms a laser beam having a uniform intensity distribution on the imaging plane, and the laser beam branching unit is provided at a position on the imaging plane, and is connected in series and so on. An organic EL panel manufacturing apparatus, which is a mask having an opening pattern of intervals. In the organic electroluminescent panel manufacturing apparatus of Claim 4,
An organic EL panel manufacturing apparatus, wherein a relay lens for converting the laser beam having two or more branches into parallel light is provided between the mask and the projection lens. In the organic electroluminescent panel manufacturing apparatus of Claim 1,
The apparatus for manufacturing an organic EL panel, wherein the laser light distribution unit includes a plurality of the laser oscillators arranged in series or in a matrix and at equal intervals. The organic EL panel manufacturing apparatus according to claim 1,
An organic EL panel manufacturing apparatus comprising an optical shutter having a function of cutting out laser light from the laser oscillator at an arbitrary time interval at an arbitrary time by a combination of a Pockels cell and a polarization beam splitter. The organic EL panel manufacturing apparatus according to claim 1,
2. The organic EL panel manufacturing apparatus according to claim 1, wherein the laser beam is an all-solid-state pulse laser beam or a continuous wave solid-state laser beam time-modulated by the optical shutter. In the organic EL panel manufacturing apparatus according to claim 1,
The organic EL panel manufacturing apparatus, wherein the donor substrate is a metal plate made of Ti, Ni, Cu, Fe, Au, Cr, Mo, W, or an alloy containing these. A first electrode made of a conductive thin film is formed on a circuit board, an organic EL layer including at least a light emitting layer is formed on the first electrode, and a second electrode formed on the organic EL layer is formed A manufacturing method of an organic EL panel to be formed,
With respect to a donor substrate in which an organic EL film is laminated on one main surface, the circuit substrate on which a lower electrode is formed is opposed to the one main surface while maintaining a certain distance from the donor substrate,
The oscillated laser beam is converted into a plurality of rectangular laser beams having a rectangular uniform intensity distribution,
Arranging a plurality of the rectangular laser beams in series and at equal intervals, and irradiating a predetermined region of the other main surface of the donor substrate with a predetermined number of times over a predetermined time,
An organic EL panel manufacturing method, wherein the organic EL film is peeled from the donor substrate and transferred onto the facing circuit substrate. In the organic electroluminescent panel manufacturing method of Claim 10,
An organic EL panel manufacturing method characterized by branching or cutting out the oscillation laser beam or the rectangular laser beam. In the organic electroluminescent panel manufacturing method of Claim 10 or 11,
The method of manufacturing an organic EL panel, wherein the predetermined time is obtained by time-modulating a pulse laser, the oscillation laser light, or the rectangular laser light. In the organic electroluminescent panel manufacturing method in any one of Claims 10 thru | or 12,
An organic EL panel manufacturing method, wherein the rectangular laser beam, the circuit board and the donor substrate are relatively moved. In the organic electroluminescent panel manufacturing method of Claim 13,
A method of manufacturing an organic EL panel, wherein the organic EL panel is moved discretely in units of equal intervals or in units of the predetermined number of times. In the organic electroluminescent panel manufacturing method in any one of Claims 10 thru | or 14,
A method of manufacturing an organic EL panel, wherein the plurality of rectangular laser beams are formed based on the oscillation laser beams from one laser oscillator or a plurality of laser oscillators arranged in series or in a matrix and at equal intervals .

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