JP2020188037A - Manufacturing method of display device and source substrate structure - Google Patents

Abstract

To provide a manufacturing method of a display device which does not leave a residual film on a light emitting element after the light emitting element is transferred from the source substrate to a drive substrate.SOLUTION: A manufacturing method of a display device includes the steps of forming a source substrate structure in which the source substrate holds a micro LED by a release layer 13 between the source substrate 14 and the micro LED 11 which transmits laser light of a predetermined wavelength, forming an adhesive layer 32 on a drive substrate 20 on which a drive substrate side electrode 21 is formed, positioning a predetermined micro LED at a predetermined position of the drive substrate, transmitting the source substrate, irradiating the micro LED with laser light 16 having a predetermined wavelength, emitting the micro LED from the release layer, and adhering the micro LED to the drive substrate, and the release layer includes a resin material formed with a film thickness of 0.1 μm or more and 0.5 μm or less.SELECTED DRAWING: Figure 8

Description

The present invention relates to a method for manufacturing a display device and a source substrate structure, and more particularly to a method for manufacturing a display device and a source substrate structure used for manufacturing the display device.

Recently, as a display device, a display device using a micro LED (micro-light emitting diode) as a light emitting element has been in the limelight. A display device using a micro LED is a next-generation display device that has a fast response speed, does not cause burning, and can display a high-brightness, high-definition image with low power consumption.

Patent Document 1 is, for example, a technique for manufacturing a display device using a micro LED. In the technique of Patent Document 1, first, a light emitting device (light emitting element) formed on a growth substrate is adhered to a transfer substrate (source substrate). After that, in the technique of Patent Document 1, laser light is irradiated from the transfer substrate side, the light emitting device is separated from the transfer substrate and moved to the backplane substrate (drive substrate). In the technique of Patent Document 1, the transfer substrate and the light emitting device are bonded to each other by forming a first adhesive layer on the light emitting device side, while the release layer and the second adhesive layer are formed on the transfer substrate in this order. Has been done. Then, the light emitting device is adhered to the transfer substrate by combining and adhering the first adhesive layer and the second adhesive layer.

In addition, as a technique for connecting the element and the substrate, for example, there are Patent Documents 2 to 4.

Special Table 2018-508971 U.S. Pat. No. 9991423 U.S. Patent Application Publication No. 2005/0269943 U.S. Pat. No. 9,484,332

In such a prior art, the transfer substrate and the light emitting device are bonded by a first adhesive layer, a second adhesive layer and a release layer containing a silicon oxide or a glass-based material. And in the prior art, it is said that the adhesive layer remaining on the light emitting device after being emitted from the transfer substrate by laser irradiation may be left as it is or may be removed by hydrofluoric acid.

However, if a residue is left on the light emitting device, the characteristics of the light emitting device are deteriorated. On the other hand, when it is removed using hydrofluoric acid, the light emitting device itself formed by the semiconductor layer may be damaged.

Therefore, the present invention provides a method for manufacturing a display device that does not leave a residual film on the light emitting element after the light emitting element is transferred from the source substrate to the drive substrate.

Another object of the present invention is to provide a source substrate structure that is used in the manufacture of a display device and does not leave a residual film on the light emitting element after the light emitting element is transferred from the source substrate to the drive substrate.

The above task is achieved by the following means.

(1) A source substrate structure forming step in which the source substrate holds the light emitting element by a release layer between the source substrate and the light emitting element that transmits laser light of a predetermined wavelength.
A drive substrate adhesive layer forming step of forming an adhesive layer on a drive substrate on which a drive substrate side electrode is formed,
A light emitting element positioning step of positioning the predetermined light emitting element with respect to the driving board in order to move the predetermined light emitting element held on the source substrate to a predetermined position of the adhesive layer on the driving board.
A light emitting element moving step of irradiating the release layer that transmits the source substrate and holding the light emitting element with a laser beam of the predetermined wavelength to move the source substrate to the surface of the adhesive layer of the driving substrate.
A light emitting element adhesion conduction step of adhering the moved light emitting element to the drive substrate via the adhesive layer and connecting the drive substrate side electrode and the light emitting element to conduct the light emitting element.
Have,
A method for manufacturing a display device, wherein the release layer contains a resin material having a film thickness of 0.1 μm or more and 0.5 μm or less.

(2) The release layer is
A first release layer containing a first resin material formed on the source substrate and
A second release layer formed on the light emitting element and containing a second resin material different from the first resin material,
Have,
The method for manufacturing a display device according to (1) above, wherein the second resin material is formed on the light emitting element with a film thickness of 0.1 μm or more and 0.5 μm or less.

(3) A release layer is provided between a source substrate that transmits laser light of a predetermined wavelength and a light emitting element, and the light emitting element is held on the source substrate by the release layer.
The release layer is a source substrate structure containing a resin material having a film thickness of 0.1 μm or more and 0.5 μm.

(4) The release layer is
The first release layer containing the first resin material and
A second release layer containing a second resin material different from the first resin material and on the light emitting element,
Have,
The source substrate structure according to (4) above, wherein the second resin material has a film thickness of 0.1 μm or more and 0.5 μm or less.

According to the present invention, a resin material coated with a film thickness of 0.1 μm or more and 0.5 μm or less was used as the release layer for adhering the source substrate and the light emitting element. Therefore, in the present invention, by irradiating the laser beam from the source substrate side, the release layer disappears and the light emitting element is emitted from the source substrate. Therefore, no residual film of the release layer remains on the light emitting element.

Further, according to the present invention, the release layer for adhering the source substrate and the light emitting element is set to two or more layers. The two or more release layers are a first release layer containing the first resin material and a second release layer containing a second resin material different from the first resin material. Of these, the second resin material contained in the second release layer on the light emitting element was applied with a film thickness of 0.1 μm or more and 0.5 μm or less. Therefore, in the present invention, when the laser beam is irradiated from the source substrate side, the second release layer disappears and the light emitting element is emitted. Therefore, no residual film of the release layer remains on the light emitting element.

It is sectional drawing which showed the micro LED forming process which concerns on the manufacturing method of the display apparatus. It is sectional drawing which showed the micro LED forming process which concerns on the manufacturing method of the display apparatus. It is sectional drawing which showed the micro LED forming process which concerns on the manufacturing method of the display apparatus. It is sectional drawing which showed the micro LED forming process which concerns on the manufacturing method of the display apparatus. It is sectional drawing which showed the micro LED forming process which concerns on the manufacturing method of the display apparatus. It is sectional drawing which showed the micro LED forming process which concerns on the manufacturing method of the display apparatus. It is sectional drawing which shows the drive board which concerns on the manufacturing method of the display apparatus. It is sectional drawing for demonstrating the connection method of the micro LED and the drive board which concerns on the manufacturing method of a display apparatus. It is sectional drawing for demonstrating the connection method of the micro LED and the drive board which concerns on the manufacturing method of a display apparatus. It is sectional drawing which shows the bonding process of a semiconductor layer and a source substrate in Embodiment 2. It is sectional drawing which shows the bonding process of a semiconductor layer and a source substrate in Embodiment 2. It is sectional drawing which shows the bonding process of a semiconductor layer and a source substrate in Embodiment 2. It is sectional drawing for demonstrating the connection method of a micro LED and a drive board in Embodiment 2.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings below, the same reference numerals refer to the same components, and in the drawings, the size of each component is also exaggerated for clarity and convenience of description. On the other hand, the embodiments described below are merely exemplary and can be modified in various ways from such embodiments.

In the following, the places described as "upper" and "above" may include not only those that are directly above in contact but also those that are not in contact and are above.

A singular expression includes multiple expressions unless they have a distinctly different meaning in the context. Also, when a part "contains" or "has" a component, it does not exclude other components unless otherwise stated to be the opposite, and may further include other components. It means good.

Also, the use of the term "above" and similar directives applies to both singular and plural.

Unless there is an explicit order or vice versa for the steps that make up the method, the steps are performed in the proper order. The order of description in the above steps is not necessarily limited. The use of all examples, or exemplary terms (eg, etc.), is solely for the purpose of explaining technical ideas and is not limited by the claims, and is scoped by the examples or exemplary terms. Is not limited.

(Embodiment 1)
A method of manufacturing a display device according to an exemplary embodiment 1 of the present invention will be described.

1 to 6 are cross-sectional views showing a micro LED forming process according to a method for manufacturing a display device.

In the micro LED forming step according to the method for manufacturing a display device, first, as shown in FIG. 1, a semiconductor layer 102 to be a micro LED (light emitting element) is formed on the sapphire substrate 101. The semiconductor layer 102 emits light having a predetermined wavelength as an LED. The semiconductor layer 102 is a GaN-based semiconductor grown on the sapphire substrate 101 or the like. At this stage, the semiconductor layer 102 is not divided into individual micro LED forms. In the present embodiment, the sapphire substrate 101 and the semiconductor layer 102 are collectively referred to as the initial substrate 100.

The sapphire substrate 101 has a size of, for example, a 4-inch wafer.

An electrode is further formed on the semiconductor layer 102 at a position corresponding to each micro LED after division. In the present embodiment, this electrode is referred to as an LED side electrode 12 (light emitting element side electrode). The division into micro LEDs will be described later.

The LED side electrode 12 is formed on the semiconductor layer 102 for each portion that becomes a micro LED after division. The LED side electrode 12 may be a part of the metal wiring electrically connected to the semiconductor layer 102 as it is, or may be formed as a metal pad in direct contact with the semiconductor layer 102.

The LED side electrode 12 is formed by using, for example, any one metal of Au, Ag, Cu, Al, Pt, Ni, Cr, Ti, and ITO or graphene. Of these, Au, Ag, and Cu are preferable.

Subsequently, as shown in FIG. 2, the relay board 112 is attached to the surface side of the initial board 100 on which the LED side electrode 12 is formed by the transfer resin layer 111. The transfer resin layer 111 is a temporary adhesive layer. This step is performed, for example, as follows. First, a transfer resin layer 111 is formed on the surface of the relay substrate 112 facing the initial substrate 100 by spin coating or the like. Subsequently, the initial substrate 100 and the relay substrate 112 are bonded together. Subsequently, the transfer resin layer 111 is cured by the heat treatment, and the initial substrate 100 and the relay substrate 112 are adhered to each other. As the relay substrate 112, for example, a quartz glass substrate is used.

For the transfer resin layer 111, it is preferable to use a resin material having an absorption rate of 60% or more and 100% or less of the laser light wavelength used in the laser lift-off described later after the resin material is cured, and more preferably 80% or more 100. % Or less resin material is used. As a specific resin material, for example, it is selected from the group consisting of a polyimide resin, an acrylic resin (for example, PMMA (Polymethyl methylate)), an epoxy resin, a PP (Polypolyrene) resin, a polycarbonate resin, and an ABS (Acrylonitril Butadiene Style) resin. Either one resin is used. When using the illustrated resin, a thermosetting agent may be blended. Further, another thermosetting resin may be used as the transfer resin layer 111.

The resin material and light have a relationship of transmittance (%) = 100% -absorption rate (%) -reflectance (%). Therefore, the absorption rate of the laser light wavelength can be obtained from this relational expression with respect to the wavelength of the laser light used in the laser lift-off. Further, the resin material has the above-mentioned laser light wavelength based on the specifications of the commercially available resin material (for example, transmittance, absorption rate, reflectance) and the characteristics of the resin material (for example, transmittance, absorption rate, reflectance). It may be selected so as to have an absorption rate.

Subsequently, as shown in FIG. 3, the sapphire substrate 101 is separated from the semiconductor layer 102. The separation of the sapphire substrate 101 uses, for example, a laser lift-off technique. Specifically, a laser beam having an ultraviolet wavelength is irradiated from the sapphire substrate 101 side so as to scan the entire surface thereof. The sapphire substrate 101 is separated from the semiconductor layer 102 by laser light irradiation. As the laser light, for example, a KrF excimer laser having a wavelength of 248 nm is used. The wavelength used is not limited to this, and any wavelength that can separate the sapphire substrate 101 from the semiconductor layer 102 may be used.

Subsequently, as shown in FIG. 4, the source substrate 14 is attached to the semiconductor layer 102 side via the release layer 13. The release layer 13 is also referred to as a dynamic release layer (DRL (Dynamic Release Layer)). This step is performed, for example, as follows. First, a resin material to be the release layer 13 is formed on the semiconductor layer 102 side by spin coating or the like. Subsequently, the source substrate 14 is attached to this resin material. Subsequently, the resin material is cured by the heat treatment to form the release layer 13, and the source substrate 14 is adhered.

The source substrate 14 transmits the wavelength of the laser light used in the laser ablation step described later. As the source substrate 14, for example, a quartz glass substrate is used. The quartz glass substrate may be, for example, the same size as or larger than the sapphire substrate 101 described above. Specifically, if the sapphire substrate 101 is a 4-inch wafer, the source substrate 14 (quartz glass substrate) is also a 4-inch wafer size. Is used.

The release layer 13 is formed by adjusting the coating film thickness according to the curing shrinkage rate of the material so that the film thickness of the resin material after curing is 0.1 μm or more and 0.5 μm or less. For example, when the curing shrinkage rate of the resin material used is 70%, the coating film thickness is 0.14 μm or more and 0.7 μm or less. Further, the coating film thickness of the resin material may be determined in advance by an experiment or the like so that the resin material to be the release layer 13 is in the above film thickness range after being cured.

For the release layer 13, it is preferable to use a resin material in which the absorption rate of the laser light used in the laser ablation step at a predetermined wavelength is 60% or more and 100% or less after the resin material to be used is cured, and more preferably 80%. More than 100% or less. The predetermined wavelength will be described later.

The resin material and light have a relationship of transmittance (%) = 100% -absorption rate (%) -reflectance (%). Therefore, the absorption rate of a predetermined wavelength can be obtained from this relational expression with respect to the wavelength of the laser light used in the laser ablation step. Further, the resin material absorbs the above-mentioned predetermined wavelength based on the specifications of the commercially available resin material (for example, transmittance, absorption rate, reflectance) and the characteristics of the resin material (for example, transmittance, absorption rate, reflectance). It may be selected so as to be a rate.

The resin material used for the release layer 13 is, for example, from a polyimide resin, an acrylic resin (for example, PMMA (Polymethyl methylate)), an epoxy resin, a polypropylene (PP (Polypolylane)) resin, a polycarbonate resin, and an ABS (Acrylonitril Butadiene Style) resin. Any one of the resins selected from the group is used. When using the illustrated resin, a thermosetting agent may be blended. Further, as the resin material, other thermosetting resins may be used.

Subsequently, as shown in FIG. 5, the relay board 112 is removed. For the removal of the relay board 112, for example, a laser lift-off technique is used. The removal of the relay board 112 is performed, for example, as follows. First, a laser beam having an ultraviolet wavelength is irradiated from the relay board 112 side so as to scan the entire surface of the relay board 112. As a result, the transfer resin layer 111 is dissolved by the irradiation of the laser light, and the relay substrate 112 is separated from the surface of the LED side electrode 12 and removed. The transfer resin layer 111 remaining on the surface of the LED side electrode 12 is removed by a cleaning treatment. The laser light used here is, for example, a KrF excimer laser having a wavelength of 248 nm. The wavelength used is not limited to this, and may be appropriately determined depending on the resin material used as the transfer resin layer 111.

Subsequently, as shown in FIG. 6, the semiconductor layer 102 is divided into a plurality of micro LEDs 11. The division into the plurality of micro LEDs 11 is divided into individual micro LEDs 11 by, for example, forming a photoresist on the semiconductor layer 102, patterning by photolithography, and dry etching using the patterned photoresist as a mask. At this stage, the release layer 13 is further patterned so as to have the same shape as the micro LED 11 using the divided micro LED 11 as a mask. The dry etching used is preferably RIE (Reactive Ion Etching), which is anisotropic etching.

The chip shape of the micro LED 11 is, for example, a polygonal shape having a side of 1 μm or more and 100 μm or less when the surface on which the LED side electrode 12 is formed is viewed as a flat surface. Preferably, one side has a rectangular shape of 1 μm or more and 100 μm or less. Further, the height of the micro LED 11, that is, the thickness of the semiconductor layer 102 is, for example, 500 μm or less. Therefore, the shape of the entire micro LED 11 is vertical × horizontal × height = 100 μm or less × 100 μm or less × 500 μm or less. The lower limit values for each of the vertical, horizontal, and height are about 1 μm, but the present invention is not limited to this, and any size may be used as long as it can be manufactured. Further, the shape of the micro LED 11 may be a circular shape, an elliptical shape, or the like. When dividing into a circular shape, the diameter is preferably 1 μm or more and 100 μm or less, and when dividing into an elliptical shape, the major axis is preferably more than 1 μm and 100 μm or less, and the minor axis is preferably 1 μm or more and less than 100 μm. In these cases as well, the lower limit of the diameter is not limited to 1 μm, and may be a size that can be manufactured.

As for the micro LEDs 11 arranged on the source substrate 14, as long as the micro LEDs 11 are surely divided from each other, the gap (interval) between them may be the minimum value that can be manufactured. Therefore, the arrangement pitch depends on the size of the micro LED 11, but is preferably 200 μm or less, for example. The arrangement pitch is, for example, the distance between the centers of adjacent micro LEDs or the distance between edges on the same side of adjacent micro LEDs.

In the first embodiment, in the steps up to this point, the source substrate structure in which the micro LED 11 is held by the source substrate 14 is provided by the one-layer release layer 13 between the source substrate 14 and the micro LED 11.

Next, the drive board will be described. FIG. 7 is a cross-sectional view showing a drive substrate according to a method for manufacturing a display device.

The drive board 20 has a size corresponding to the size of the display device to be manufactured.

The drive board 20 is formed with an electrode for connecting to the LED side electrode 12 together with wiring and a TFT (thin-film-transistor) necessary for supplying electric power to the micro LED 11. In the present embodiment, the electrodes provided on the drive substrate 20 are referred to as drive substrate side electrodes 21. The drive board side electrode 21 may be a part of the metal wiring formed on the drive board 20 as it is, or may be formed as a metal pad connected to the wiring. As the drive board side electrode 21, the same metal as the LED side electrode 12 described above is used.

In the first embodiment, the adhesive layer 32 is formed on the surface of the drive substrate 20 on which the drive substrate side electrodes 21 are formed. For the adhesive layer 32, for example, NCF (Nonconductive Film), NCP (Nonconducive paste), NCA (NonConductive Adhesive), which are non-conductive adhesives, and the like are used. Further, as the adhesive layer, for example, an epoxy resin, an acrylic resin, a polyamide resin, a polyacrylamide resin, polyvinyl alcohol, polyvinylpyrrolidone, or the like mixed with a thermosetting agent may be used. The adhesive layer 32 is not limited to these, and a thermosetting resin can be used. Further, a photoresist (positive type) may be used for the adhesive layer 32.

The adhesive layer 32 is applied to the entire surface of the drive substrate 20 on which the drive substrate side electrodes 21 are formed, for example, by a laminating method or a printing method. The thickness of the adhesive layer 32 is, for example, 1 μm or more and 50 μm or less. In the connection between the micro LED 11 and the drive substrate 20, which will be described later, there are pressurizing and heating steps. In the first embodiment, by setting the thickness of the adhesive layer 32 to 1 μm or more and 50 μm or less, the LED side electrode 12 can reach the drive substrate side electrode 21 by this pressurizing and heating step.

In the first embodiment, the drive board structure provided with the adhesive layer 32 is provided in the steps up to this point.

Next, the connection between the micro LED 11 and the drive board 20 will be described. 8 and 9 are cross-sectional views for explaining a method of connecting the micro LED 11 and the drive substrate 20 according to the method of manufacturing a display device.

Laser ablation technology is used to connect the micro LED 11 and the drive substrate 20. As shown in FIG. 8, first, in order to connect one micro LED 11 to the drive board 20, the entire source board 14 is moved and positioned. The positioning at this time is moved to a position where the LED side electrode 12 of one micro LED 11 can be connected to the corresponding drive board side electrode 21 for driving the micro LED 11.

After positioning, a laser beam 16 having a predetermined wavelength (ultraviolet rays (UV)) is irradiated from the source substrate 14 side toward one micro LED 11. When the laser beam 16 is irradiated, the release layer 13 holding one micro LED 11 is decomposed and disappears, and the micro LED 11 is emitted to the drive substrate 20 side. The emitted micro LED 11 is caught by the adhesive layer 32 on the drive substrate 20 side. The predetermined wavelength of the laser light 16 used is, for example, a KrF excimer laser having a wavelength of 248 nm. In addition, YAG (FHG) having a wavelength of 266 nm, YAG (THG) having a wavelength of 355 nm, and the like are used. In particular, for a laser having a wavelength of 355 nm, a glass substrate can be used instead of the quartz glass substrate, which is more advantageous in terms of member and device costs. Therefore, the predetermined wavelength is, for example, a wavelength of 248 nm or more and 355 nm or less. Laser light of other wavelengths may be used.

The beam diameter of the laser beam 16 may be the same as or larger than the chip size of one micro LED 11. However, it is preferable that the beam diameter of the laser beam 16 is large enough not to affect the adjacent micro LED 11 on the source substrate 14. By setting the beam diameter of the laser beam 16 as described above, the micro LEDs 11 arranged on the source substrate 14 can be selectively transferred to the drive substrate 20 side one by one.

The number of beams of the laser light 16 may be one, but a plurality of beams may be simultaneously irradiated at a desired pitch by using a mask or the like or by preparing a plurality of laser light sources. By doing so, a large number of micro LEDs 11 can be transferred at the same time.

Further, when the laser ablation step is performed, the gap between the micro LED 11 and the drive substrate 20 is preferably 70 μm or more and 100 μm or less, for example. By setting such a gap interval, the micro LED 11 emitted from the source substrate 14 in the laser ablation step can be caught at the target position of the drive substrate 20. Further, although it depends on the operating accuracy of the bonding apparatus, by setting the lower limit of the gap interval to 70 μm, when the source substrate 14 is moved by the bonding apparatus, the source substrate 14 is moved at high speed without contacting the drive substrate 20. be able to. The gap interval is the interval at the position closest to each other when the source substrate 14 and the drive substrate 20 face each other. The distance between the closest positions is usually the position where the LED side electrode 12 and the adhesive layer 32 on the drive board side electrode 21 face each other. The emission of the micro LED 11 from the source substrate 14 and the adhesion to the drive substrate 20 by the laser light are repeated as many times as necessary for the display device.

Subsequently, when the required number of micro LEDs 11 are arranged on the drive substrate 20, the micro LEDs 11 are relatively pressed toward the drive substrate 20 to bring them into close contact with each other and heat them. The pressing force at this time is such that the LED side electrode 12 and the drive board side electrode 21 are connected. The heating temperature is the temperature at which the adhesive layer 32 is cured. This heating temperature is, for example, when NCF, NCP, or NCA containing a thermosetting resin is used, the curing temperature is 100 ° C. or higher and 200 ° C. or lower when the pressure is 1 MPa or more and 10 MPa or less, although it depends on the pressing force. ..

As a result, as shown in FIG. 9, the LED side electrode 12 and the drive board side electrode 21 are electrically connected and conducted, and the micro LED 11 and the drive board 20 are adhered by the cured adhesive layer 32.

As a manufacturing method of the display device 10, if there are further necessary peripheral circuit connections and wirings, those are formed and wiring steps are performed, and resin molding and the like are performed to protect the micro LED 11. The display device 10 is completed.

According to the first embodiment, the following effects are obtained.

In the first embodiment, a resin material is formed as a release layer 13 in which the source substrate 14 holds the micro LED 11 and has a film thickness of 0.1 μm or more and 0.5 μm or less. Since the extremely thin release layer 13 is decomposed and disappears by irradiation with laser light, the resin component of the release layer 13 does not remain on the micro LED 11 after being emitted from the source substrate 14. Therefore, in the first embodiment, the residual film treatment and the cleaning step after the laser ablation step are not required, and the manufacturing cost can be reduced.

Further, in the first embodiment, since no residual film remains on the micro LED 11, the optical characteristics of the light emitted from the micro LED 11 do not deteriorate.

Further, in the first embodiment, since no residual film remains on the micro LED 11, problems such as poor adhesion and repelling do not occur when resin molding is performed on the micro LED 11.

Further, in the first embodiment, since the absorption rate of the laser light in the release layer 13 is as high as 60% or more, the release layer 13 can be decomposed more quickly. Therefore, since the energy of the laser light emitted by the laser ablation step can be reduced, the damage to the micro LED 11 caused by the laser light can be prevented or extremely reduced.

Further, in the first embodiment, the energy of the laser light emitted by the laser ablation step can be reduced. Therefore, the first embodiment can stabilize the transfer position accuracy when the micro LED 11 is emitted from the source substrate 14. The laser ablation step not only decomposes and eliminates the release layer 13 with the energy of the laser light, but also has the effect of ejecting the micro LED 11. Therefore, in the laser ablation step, if the energy of the laser light is too strong, the micro LED 11 is ejected with a strong force, and the emission direction of the micro LED 11 becomes unstable. In this respect, in the first embodiment, the energy can be reduced, and as a result, the force for ejecting the micro LED 11 is weakened, and the direction in which the micro LED 11 is emitted is stabilized.

Further, in the first embodiment, since the direction in which the micro LED 11 is emitted is stable in this way, the gap between the source substrate 14 and the drive substrate 20 can be made relatively wide. Therefore, in the first embodiment, the gap margin can be widened. Therefore, in the first embodiment, when the micro LED 11 is transferred to the drive board 20 larger than the source board 14, the operation of continuously moving the source board 14 can be realized relatively easily, and the process time can be reduced. Can be shortened.

Further, in the first embodiment, since the energy of the laser light emitted by the laser ablation step can be reduced, the generation of plasma generated in the laser ablation step can be reduced. As described above, in the first embodiment, the plasma generated in the laser ablation step can be reduced, so that the damage to the source substrate 14 due to the plasma can be prevented or extremely reduced. As a result, in the first embodiment, the source substrate 14 after emitting the micro LED 11 can be easily reused, and the manufacturing cost can be reduced. This is because, conventionally, when the source substrate 14 is reused, it is necessary to mirror the surface damaged by the plasma by a polishing process. In this respect, in the first embodiment, the source substrate 14 can be damaged or extremely reduced. Therefore, in the first embodiment, the polishing work when reusing the source substrate 14 can be eliminated or the number of times of polishing can be reduced, so that the cost for reusing the source substrate 14 can be reduced.

Further, in the first embodiment, the energy of the laser beam irradiated by the laser ablation step can be reduced, so that the energy saving of the manufacturing process can be achieved. For example, in the case of manufacturing a display device having a 4K resolution, it is necessary to transfer the micro LED 11 having about 8 million pixels to the drive substrate 20. When one pixel is composed of one micro LED 11 for each of RGB, about 24 million micro LEDs 11 are simply emitted one by one by laser irradiation. Therefore, in the first embodiment, the energy of the laser beam can be reduced, so that the manufacturing cost can be reduced.

(Embodiment 2)
A method of manufacturing a display device according to an exemplary embodiment 2 of the present invention will be described.

The second embodiment has two or more layers made of different resin materials as a release layer between the source substrate 14 and the micro LED 11. The same as in the first embodiment except for the configuration other than the release layer and the manufacturing process of the release layer. Further, the members described in the first embodiment and the members having the same functions are designated by the same reference numerals even when the arrangement is different.

10 to 12 are cross-sectional views showing a step of adhering the semiconductor layer 102 and the source substrate 14 in the second embodiment. Further, FIG. 13 is a cross-sectional view for explaining a method of connecting the micro LED 11 and the drive board 20 in the second embodiment.

In the second embodiment, as shown in FIG. 10, a first resin material to be the first release layer 131 is applied to the source substrate 14 before the semiconductor layer 102 is adhered. The first resin material to be the first release layer 131 is, for example, a polydimethylsiloxane (PDMS) resin. The film thickness of the first release layer 131 is 1 μm or more and 5 μm or less at the time of coating. After coating, the first resin material is heated and fired to become the first release layer 131. After the first resin material is cured, the film thickness of the first release layer 131 is, for example, 1 μm or more and 5 μm or less. The film thickness of the first release layer 131 is the same before and after curing because the specific gravity of the polydimethylsiloxane (PDMS) resin, which is the first resin material, before and after curing is less than the measurement limit. Of course, the film thickness before and after curing differs depending on the resin material used. In such a case, after the first resin material to be the first release layer 131 is cured, the coating film thickness may be adjusted so that the film thickness is within the above range.

The absorption rate of the first release layer 131 made of the first resin material at a predetermined wavelength is 1% or more and 50% or less. This predetermined wavelength is the wavelength of the laser light used in the laser ablation step as in the first embodiment. The absorption rate of the predetermined wavelength in the first resin material can be obtained by using the relational expression of transmittance (%) = 100% -absorption rate (%) -reflectance (%) as in the first embodiment. .. That is, the absorption rate of a predetermined wavelength is obtained from this relational expression with respect to the wavelength of the laser light used in the laser ablation step. Further, as in the first embodiment, the first resin material includes specifications of a commercially available resin material (for example, transmittance, absorption rate, reflectance) and characteristics of the resin material (for example, transmittance, absorption rate, reflectance). Therefore, it may be selected so as to have the above-mentioned transmittance of the predetermined wavelength.

Further, in the second embodiment, as shown in FIG. 11, a second resin material to be the second release layer 132 is applied onto the semiconductor layer 102 held on the relay substrate 112. The second release layer 132 is formed by adjusting the coating film thickness so that the film thickness of the second resin material after curing is 0.1 μm or more and 0.5 μm or less. For example, when the curing shrinkage rate of the second resin material to be used is 70%, the coating film thickness is 0.14 μm or more and 0.7 μm or less. Further, the coating film thickness of the second resin material may be determined in advance by an experiment or the like so that the film thickness of the second resin material to be the second release layer 132 is within the above film thickness range after curing. Therefore, this second resin material has the same structure as the resin material forming the release layer in the first embodiment.

Therefore, the relationship between the film thicknesses of the first release layer 131 and the second release layer 132 is T1> T2, where T1 is the film thickness of the first release layer 131 and T2 is the film thickness of the second release layer 132. There is.

The second resin material is the same as the resin material used for the release layer 13 of the first embodiment. That is, the second resin material consists of, for example, a group consisting of a polyimide resin, an acrylic resin (for example, PMMA (Polymethyl methylate)), an epoxy resin, a polypropylene (PP (Polypolylane)) resin, a polycarbonate resin, and an ABS (Acrylonitril Butadiene Style) resin. Any one of the selected resins is used. When using the illustrated resin, a thermosetting agent may be blended. Further, as the resin material, other thermosetting resins may be used.

After the resin material is cured, the second release layer 132 preferably has an absorption rate of 60% or more and 100% or less at a predetermined wavelength, and more preferably 80% or more and 100% or less. The predetermined wavelength is, for example, a wavelength of 248 nm or more and 355 nm or less, as in the first embodiment. The absorption rate of the predetermined wavelength in the second resin material can be obtained by using the relational expression of transmittance (%) = 100% -absorption rate (%) -reflectance (%) as in the first embodiment. .. That is, the absorption rate of a predetermined wavelength is obtained from this relational expression with respect to the wavelength of the laser light used in the laser ablation step. Further, as in the first embodiment, as the second resin material, the specifications of the commercially available resin material (for example, transmittance, absorption rate, reflectance) and the characteristics of the resin material (for example, transmittance, absorption rate, reflectance) Therefore, it may be selected so as to have the above-mentioned transmittance of the predetermined wavelength.

As described above, in the second embodiment, the first release layer 131 is formed on the side close to the source substrate 14, and the second release layer 132 is formed on the semiconductor layer 102 side which becomes the micro LED 11.

The first release layer 131 and the second release layer 132 have different absorption rates at a predetermined wavelength, and the absorption rate at the predetermined wavelength of the first release layer 131 is the absorption rate at the predetermined wavelength of the second release layer 132. Lower. That is, the relationship between the absorption rate of the predetermined wavelength of the first release layer 131 and the second release layer 132 is such that the absorption rate of the predetermined wavelength of the first release layer 131 is Wa1 and the absorption rate of the predetermined wavelength of the second release layer 132 is set. If it is Wa2, Wa1 <Wa2.

Subsequently, in the second embodiment, as shown in FIG. 12, the first release layer 131 and the second release layer 132 face each other, the source substrate 14 and the relay substrate 112 are bonded to each other, and pressure heating is performed. As a result, the first release layer 131 and the second release layer 132 are adhered to each other.

After that, in the second embodiment, similarly to the first embodiment, the relay substrate 112 is removed by laser lift-off, and the surface of the semiconductor layer 102 is cleaned.

After that, in the second embodiment, the semiconductor layer 102 is divided into the micro LEDs 11 as in the first embodiment. At this time, at least the second release 132 layer is divided according to the size of the micro LED 11 as in the first embodiment, but the first release layer 131 may or may not be divided. .. That is, the first release layer 131 may be overetched when the second release 132 layer is etched using the divided micro LED 11 as a mask.

Thereby, in the second embodiment, the source substrate structure in which the micro LED 11 is held in the source substrate 14 is provided by the first release layer 131 and the second release layer 132 between the source substrate 14 and the micro LED 11. ..

In the second embodiment, as shown in FIG. 13, each micro LED 11 is transferred to the drive substrate 20 by the laser ablation step. The laser ablation step in the second embodiment is basically the same as that in the first embodiment, and the laser light having a predetermined wavelength described in the first embodiment is used.

After that, also in the second embodiment, if a predetermined number of micro LEDs 11 are transferred to the drive substrate 20, the pressurizing and heating step is performed as in the first embodiment. As a result, also in the second embodiment, the micro LED 11 is adhered to the drive substrate 20, and the LED side electrode 12 and the drive substrate side electrode 21 are electrically connected and conducted. Then, also in the second embodiment, the necessary peripheral circuit connection and wiring steps are performed, and resin molding and the like are performed to protect the micro LED 11, and the display device 10 is completed (see FIG. 9). ..

According to the second embodiment, the following effects are obtained.

In the second embodiment, the source substrate 14 and the micro LED 11 are held by using two or more release layers (first release layer 131 and second release layer 132). Of these, the second release layer 132 on the micro LED 11 side had a film thickness of 0.1 μm or more and 0.5 μm or less when the second resin material to be the second release layer 132 was applied. Therefore, also in the second embodiment, as in the first embodiment, no residual film is generated on the micro LED 11 emitted by the laser ablation step. Therefore, the residual film treatment and the cleaning step after the laser ablation step are not required.

Further, in the second embodiment, the absorption rate of the predetermined wavelength of the first release layer 131 is 1% or more and 50% or less, and the absorption rate of the predetermined wavelength of the second release layer 132 is 60% or more and 100% or less. As a result, in the second embodiment, even if the energy of the laser light emitted by the laser ablation step is higher than that of the first embodiment, it can be absorbed by the first release layer 131. Therefore, in the second embodiment, the energy of the laser light reaching the micro LED 11 is reduced, so that the micro LED 11 is stably activated when it is emitted, as in the first embodiment. Therefore, in the second embodiment as well, the gap margin between the source substrate 14 and the drive substrate 20 can be widened as in the first embodiment. Further, also in the second embodiment, since the energy of the laser light reaching the micro LED 11 is reduced, the damage to the micro LED 11 due to the laser light can be prevented or extremely reduced.

Further, in the second embodiment, the second release layer 132 divided into the same shape as the individual micro LEDs 11 disappears by the laser ablation step, but the first release layer 131 remains on the source substrate 14. Therefore, in the second embodiment, the surface of the source substrate 14 to which the semiconductor layer 102 is attached is protected by the remaining first release layer 131 from the plasma generated in the laser ablation step. Therefore, the second embodiment can prevent the source substrate 14 from being damaged by the plasma generated in the laser ablation step. As a result, the source substrate 14 after the micro LED 11 is emitted can be easily reused, and the manufacturing cost can be reduced. This is because, conventionally, when the source substrate 14 is reused, it is necessary to mirror the surface damaged by the plasma by a polishing process. In this respect, in the second embodiment, the source substrate 14 can be damaged or extremely reduced. Therefore, in the second embodiment, the polishing work when reusing the source substrate 14 can be eliminated or the number of times of polishing can be reduced, so that the cost for reusing the source substrate 14 can be reduced.

Hereinafter, an example in which the display device 10 is prototyped will be described.

<Example 1>
(Creation of source board)
In the first embodiment, first, a semiconductor layer 102 to be an LED and an LED side electrode 12 are formed on a 4-inch size sapphire substrate 101. The LED side electrode 12 is a gold (Au) pad formed directly on the semiconductor layer 102. The size of the LED side electrode (pad) was 30 × 20 μm. The film thickness of the semiconductor layer 102 was 5 μm.

Subsequently, a polyimide resin containing a thermosetting agent was spin-coated on the relay substrate 112 with a film thickness of 10 μm to form a transfer resin layer 111. A quartz glass substrate was used as the relay substrate 112.

Subsequently, the sapphire substrate 101 and the relay substrate 112 are overlapped with each other so that the semiconductor layer 102 and the transfer resin layer 111 are in contact with each other, and the two substrates are bonded together by pressurizing and heating at 1000 N and 250 ° C. for 10 minutes. It was.

Subsequently, a KrF excimer laser having a wavelength of 248 nm was irradiated over the entire surface from the sapphire substrate 101 side at an energy density of 200 mJ / cm ² , and the semiconductor layer 102 and the sapphire substrate 101 were separated.

Subsequently, a quartz glass substrate is prepared as the source substrate 14, and a polyimide resin containing a thermosetting agent is spin-coated on the source substrate 14 to form a resin layer having a film thickness of 0.15 μm, and a vacuum oven is used. The release layer 13 was formed by firing at 250 ° C. for 1 hour. As the polyimide resin, HD3007 (HD MicroSystems) diluted to a desired solid content concentration was used. After curing, HD3007 has an ultraviolet absorption rate of 99% or more at a wavelength of 248 nm.

Subsequently, the surface of the semiconductor layer 102 on the relay board 112 is superposed on the release layer 13 of the source board 14, and the source board 14 is pressurized and heated at a pressure of 1000 N at 250 ° C. for 10 minutes using a bonding device. And the relay board 112 were bonded together.

Subsequently, a KrF excimer laser having a wavelength of 248 nm was irradiated over the entire surface from the relay substrate 112 side at an energy density of 200 mJ / cm ² , and the transfer resin layer 111 and the relay substrate 112 were separated. In order to remove the transfer resin remaining on the semiconductor layer 102, N-methylpyrrolidone (NMP) was sprayed on the surface of the transfer resin at 60 ° C. for 60 seconds. Then, it was rinsed with pure water for 60 seconds.

Subsequently, the semiconductor layer 102 was divided into individual micro LEDs 11 by dry etching (RIE). Further, using the divided micro LED 11 as a mask, the release layer 13 was etched by oxygen plasma RIE and divided according to the shape of the micro LED 11.

(Transfer by laser ablation process)
The TFTs were arranged on the array at regular intervals, and the drive board 20 with copper (Cu) wiring connected to the TFTs was prepared. A part of the copper wiring becomes the drive board side electrode 21.

An adhesive layer 32 was formed by applying a non-conductive material composed of an epoxy resin and a thermosetting agent to the entire surface of the drive substrate 20 on which the drive substrate side electrodes 21 are arranged using an applicator. The adhesive layer 32 had a film thickness of 5 μm on the drive substrate side electrode 21.

Subsequently, the surface of the source substrate 14 on which the micro LED 11 is held and the surface of the drive substrate 20 on which the drive substrate side electrode 21 is arranged are held facing each other with a gap of 100 μm. At this time, one micro LED 11 to be transferred was positioned at a target position on the drive substrate 20.

Subsequently, the micro LED 11 was transferred to the drive substrate 20 by a laser ablation step. In the laser ablation step, a KrF excimer laser having a wavelength of 248 nm was irradiated from the source substrate 14 side to one micro LED 11 to be transferred with an irradiation energy density of 100 mJ / cm ² . The diameter of the laser beam is such that one micro LED 11 or more and the adjacent micro LED 11 is not irradiated with the laser beam.

As a result, one micro LED 11 was emitted from the source substrate 14 and caught at the target position of the drive substrate 20.

In the same manner, the required number of micro LEDs 11 were repeatedly transferred onto the drive substrate 20.

Subsequently, the micro LED 11 was fixed to the drive substrate 20 by the pressurizing and heating steps. In the pressurizing and heating steps, the entire surface of the drive substrate 20 is pressurized so that the LED side electrode 12 and the drive substrate side electrode 21 are in contact with each other through the epoxy resin, and the epoxy is epoxy at a temperature of 250 ° C. The resin was thermoset.

As described above, the required number of micro LEDs 11 as a display panel was transferred onto the drive substrate 20.

The surface of the micro LED 11 after being transferred to the drive substrate 20 was observed without cleaning. As a result, there was no residual film of the polyimide resin which is the release layer 13 on the surface of the micro LED 11 after the transfer. In addition, no damage such as laser marks was detected on the surface of the micro LED 11.

<Example 2>
In Example 2, the film thickness of the release layer 13 when the resin material was applied was set to 0.5 μm. Other steps and materials are the same as in Example 1.

The surface of the micro LED 11 after being transferred to the drive substrate 20 was observed without cleaning. As a result, there was no residual film of the polyimide resin which is the release layer 13 on the surface of the micro LED 11 after the transfer. In addition, no damage such as laser marks was detected on the surface of the micro LED 11.

<Comparative example 1>
In Comparative Example 1, the film thickness of the release layer 13 when the resin material was applied was set to 0.7 μm. Other steps and materials are the same as in Example 1.

The surface of the micro LED 11 after being transferred to the drive substrate 20 was observed without cleaning. As a result, a residual film of the polyimide resin, which is the release layer 13, was detected on the surface of the micro LED 11 after transfer.

<Example 3>
Example 3 was the same as that of Example 1 until the semiconductor layer 102 was adhered onto the relay substrate 112.

In Example 3, a dimethylpolysiloxane (PDMS) resin containing a thermosetting catalyst was applied to the source substrate 14 with a film thickness of 10 μm using a slit coating, and fired in an oven at 150 ° C. for 1 hour. A 1-release layer 131 was formed.

The first release layer 131 formed by firing a dimethylpolysiloxane (PDMS) resin has an ultraviolet absorption rate of 35% at a wavelength of 248 nm.

Separately, a polyimide resin is formed on the surface of the semiconductor layer 102 adhered on the relay substrate 112 to a film thickness of 0.1 μm by a spin coating method, and fired in a vacuum oven at 250 ° C. for 1 hour to form a second release layer. 132 was formed. As the polyimide resin, HD3007 (HD MicroSystems) diluted to a desired solid content concentration was used. After curing, HD3007 has an ultraviolet absorption rate of 99% or more at a wavelength of 248 nm.

Subsequently, the source substrate 14 and the relay substrate 112 are overlapped with the first release layer 131 and the second release layer 132 facing each other, and the pressure is 10 N / cm ² at room temperature of 20 ° C. or higher and 30 ° C. or lower using a vacuum bonding apparatus. Pressurized and bonded.

Subsequently, similarly to Example 1, a KrF excimer laser having a wavelength of 248 nm was irradiated over the entire surface from the relay substrate 112 side at an energy density of 200 mJ / cm ² , and the transfer resin layer 111 and the relay substrate 112 were separated. Then, N-methylpyrrolidone (NMP) was sprayed on the surface of the transfer resin at 60 ° C. for 60 seconds, and then rinsed with pure water for 60 seconds.

Subsequently, the semiconductor layer 102 was divided into individual micro LEDs 11 by dry etching (RIE). Further, using the divided micro LED 11 as a mask, the release layer 13 was etched by oxygen plasma RIE and divided according to the shape of the micro LED 11.

(Transfer by laser ablation process)
The transfer by the laser ablation step was carried out in the same manner as in Example 1. That is, the adhesive layer 32 was formed on the drive substrate side electrode 21 so as to have a film thickness of 5 μm.

Subsequently, the surface of the source substrate 14 on which the micro LED 11 is held and the surface of the drive substrate 20 on which the drive substrate side electrode 21 is arranged are held facing each other with a gap of 100 μm. At this time, one micro LED 11 to be transferred was positioned at a target position on the drive substrate 20.

Subsequently, the micro LED 11 was transferred to the drive substrate 20 by a laser ablation step. In the laser ablation step, a KrF excimer laser having a wavelength of 248 nm was irradiated from the source substrate 14 side to one micro LED 11 to be transferred with an irradiation energy density of 100 mJ / cm ² . The diameter of the laser beam is such that one micro LED 11 or more and the adjacent micro LED 11 is not irradiated with the laser beam.

As a result, one micro LED 11 was emitted from the source substrate 14 and caught at the target position of the drive substrate 20.

In the same manner, a required number of micro LEDs 11 were repeatedly transferred onto the drive substrate 20, and then the micro LEDs 11 were fixed onto the drive substrate 20 by a pressurizing and heating step. In the pressurizing and heating steps, the entire surface of the drive substrate 20 is pressurized so that the LED side electrode 12 and the drive substrate side electrode 21 are in contact with each other, and heat treatment is performed in an oven at 200 ° C. for 1 hour to heat-cure the epoxy resin. It was.

As described above, the required number of micro LEDs 11 as a display panel was transferred onto the drive substrate 20.

Also in Example 3, the surface of the micro LED 11 after being transferred to the drive substrate 20 was observed without cleaning. As a result, there was no residual film of the polyimide resin which is the second release layer 132 on the surface of the micro LED 11 after the transfer. In addition, no damage such as laser marks was detected on the surface of the micro LED 11.

Although the embodiments and examples of the present invention have been described above, the present invention is not limited to these embodiments and examples, and various modifications can be made.

In each of the above-described embodiments, the LED side electrode 12 and the drive substrate side electrode 21 are directly contacted and joined, but they may be connected to each other via a metal layer. Specifically, for example, a solder bump is formed and placed on at least one of the LED side electrode 12 and the drive substrate side electrode 21. Then, in the heating step for curing the adhesive layer after transferring the micro LED by the laser ablation step, the electrode can be connected by the metal layer by setting the temperature as the reflow temperature of the solder bump.

Further, in the second embodiment described above, the micro LED 11 is held by the two release layers of the first release layer 131 and the second release layer 132 on the source substrate 14, but instead of this, three or more layers are released. The micro LED 11 may be held by the layer. In the case of providing three or more release layers, for example, a first resin material to be the first release layer is applied to the source substrate 14 side, and a third resin material to be the third release layer is further applied thereto. Apply.

Here, the third resin material has a different absorption rate of a predetermined wavelength after curing from, for example, the first release layer 131 and the second release layer 132.

Providing such three or more release layers can be achieved by adding a third release layer, for example, when the effect of reducing the energy of the laser light is low with only one layer of the first release layer. , Energy can be further reduced. That is, in the second embodiment, the amount of energy of the laser light reaching the micro LED 11 can be controlled by the number of layers of the release layer. The absorption rate of the predetermined wavelength of the third release layer is preferably 1% or more and 50% or less, as in the case of the first release layer 131. However, from the viewpoint of reliably decomposing the second release layer 132, it is preferable that the absorption rate of the predetermined wavelength including the first release layer and the third release layer does not exceed 50%.

Further, the present invention may further have a plurality of release layers. In that case, it is preferable that each release layer is made of a different resin material.

In addition, the present invention can be modified in various ways based on the configurations described in the claims, and these are also within the scope of the present invention.

10 Display device,
11 micro LED,
12 LED side electrodes,
13 release layer,
14 Source board,
16 laser light,
20 drive board,
21 Drive board side electrode,
32 Adhesive layer,
100 initial board,
101 sapphire substrate,
102 Semiconductor layer,
111 Transfer resin layer,
112 relay board,
131 1st release layer,
132 Second release layer.

Claims (22)

A step of forming a source substrate structure in which the source substrate holds the light emitting element by a release layer between the source substrate and the light emitting element that transmits laser light of a predetermined wavelength.
A drive substrate adhesive layer forming step of forming an adhesive layer on a drive substrate on which a drive substrate side electrode is formed,
A light emitting element positioning step of positioning the predetermined light emitting element with respect to the driving board in order to move the predetermined light emitting element held on the source substrate to a predetermined position of the adhesive layer on the driving board.
A light emitting element moving step of irradiating the release layer that transmits the source substrate and holding the light emitting element with a laser beam of the predetermined wavelength to move the source substrate to the surface of the adhesive layer of the driving substrate.
A light emitting element adhesion conduction step of adhering the moved light emitting element to the drive substrate via the adhesive layer and connecting the drive substrate side electrode and the light emitting element to conduct the light emitting element.
Have,
A method for manufacturing a display device, wherein the release layer contains a resin material having a film thickness of 0.1 μm or more and 0.5 μm or less. The source substrate structure forming step is
An electrode is formed on the semiconductor layer formed on the sapphire substrate, and the electrode is formed.
A temporary adhesive layer is formed on the surface side on which the electrodes are formed, and a temporary adhesive layer is formed.
The electrode surface side is adhered to the relay substrate via the temporary adhesive layer,
Remove the sapphire substrate and remove
The source substrate is held on the surface of the semiconductor layer from which the sapphire substrate has been removed via the release layer.
After removing the temporary adhesive layer and the relay board,
Unnecessary parts of the semiconductor layer are removed and divided,
A light emitting element forming step of forming a plurality of the light emitting elements on the source substrate via the release layer.
The method for manufacturing a display device according to claim 1. The method for manufacturing a display device according to claim 1 or 2, wherein the release layer has an absorption rate of 60% or more and 100% or less at the predetermined wavelength. The resin material according to any one of claims 1 to 3, wherein the resin material contains any one resin selected from the group consisting of a polyimide resin, an acrylic resin, an epoxy resin, a polypropylene resin, a polycarbonate resin, and an ABS resin. How to manufacture a display device. The release layer is
A first release layer containing a first resin material formed on the source substrate and
A second release layer formed on the light emitting element and containing a second resin material different from the first resin material,
Have,
The method for manufacturing a display device according to claim 1, wherein the second resin material is formed on the light emitting element with a film thickness of 0.1 μm or more and 0.5 μm or less. The source substrate structure forming step is
A first release layer forming step of preparing the source substrate and applying the first resin material on the source substrate to form the first release layer.
An electrode is formed on the semiconductor layer formed on the sapphire substrate, and the electrode is formed.
A temporary adhesive layer is formed on the surface side on which the electrodes are formed, and a temporary adhesive layer is formed.
The electrode surface side is adhered to the relay substrate via the temporary adhesive layer,
Remove the sapphire substrate and remove
The second resin material is applied to the surface of the semiconductor layer from which the sapphire substrate has been removed so that the film thickness after curing is 0.1 μm or more and 0.5 μm or less to form the second release layer. 2 release layer forming process and
The first release layer and the second release layer are opposed to each other, the source substrate and the relay substrate are bonded to each other, and the semiconductor is placed on the source substrate via the first release layer and the second release layer. The layer is transferred, the relay substrate is removed, unnecessary portions of the semiconductor layer are removed and divided, and a plurality of the light emitting elements are placed on the source substrate via the first release layer and the second release layer. And the light emitting element forming process to form
The method for manufacturing a display device according to claim 5. The relationship between the absorption rate of the predetermined wavelength of the first release layer and the second release layer is such that the absorption rate of the predetermined wavelength of the first release layer is Wa1 and the absorption rate of the predetermined wavelength of the second release layer. The method for manufacturing a display device according to claim 5 or 6, wherein when is Wa2, Wa1 <Wa2. The absorption rate of the predetermined wavelength of the first release layer is 1% or more and 50% or less, and the absorption rate of the predetermined wavelength of the second release layer is 60% or more and 100% or less. The method for manufacturing a display device according to any one of them. The relationship between the film thickness of the first release layer and the film thickness of the second release layer is T1> T2, where T1 is the film thickness of the first release layer and T2 is the film thickness of the second release layer. The method for manufacturing a display device according to any one of 5 to 8. The method for manufacturing a display device according to any one of claims 5 to 9, wherein the film thickness of the first release layer is 1 μm or more and 5 μm or less. The first resin material contains a polydimethylsiloxane resin and contains.
Any one of claims 5 to 10, wherein the second resin material contains any one resin selected from the group consisting of a polyimide resin, an acrylic resin, an epoxy resin, a polypropylene resin, a polycarbonate resin, and an ABS resin. The method for manufacturing a display device according to. The method for manufacturing a display device according to any one of claims 1 to 11, wherein the predetermined wavelength is a wavelength of 248 nm or more and 355 nm or less. The light emitting element has a polygonal shape having a side of 1 μm or more and 100 μm or less, a circular shape having a diameter of 1 μm or more and 100 μm or less, or an elliptical shape having a major axis of more than 1 μm and 100 μm or less and a minor axis of 1 μm or more and less than 100 μm. Item 2. The method for manufacturing a display device according to any one of Items 1 to 12. A release layer is provided between a source substrate that transmits laser light of a predetermined wavelength and a light emitting element, and the light emitting element is held on the source substrate by the release layer.
The release layer is a source substrate structure containing a resin material having a film thickness of 0.1 μm or more and 0.5 μm. The source substrate structure according to claim 14, wherein the release layer has an absorption rate of 60% or more and 100% or less at the predetermined wavelength. The source substrate structure according to claim 14 or 15, wherein the resin material is any one resin selected from the group consisting of a polyimide resin, an acrylic resin, an epoxy resin, a polypropylene resin, a polycarbonate resin, and an ABS resin. .. The release layer is
The first release layer containing the first resin material and
A second release layer containing a second resin material different from the first resin material and on the light emitting element,
Have,
The source substrate structure according to claim 14, wherein the second resin material has a film thickness of 0.1 μm or more and 0.5 μm or less. The relationship between the absorption rate of the predetermined wavelength of the first release layer and the second release layer is such that the absorption rate of the predetermined wavelength of the first release layer is Wa1 and the absorption rate of the predetermined wavelength of the second release layer. The source substrate structure according to claim 17, wherein when is Wa2, Wa1 <Wa2. 17 or 18, the absorption rate of the predetermined wavelength of the first release layer is 1% or more and 50% or less, and the absorption rate of the predetermined wavelength of the second release layer is 60% or more and 100% or less. The source board structure described. The first resin material contains a polydimethylsiloxane resin and contains.
Any one of claims 17 to 19, wherein the second resin material contains any one resin selected from the group consisting of polyimide resin, acrylic resin, epoxy resin, polypropylene resin, polycarbonate resin, and ABS resin. The source substrate structure described in. The source substrate structure according to any one of claims 17 to 20, wherein the predetermined wavelength is a wavelength of 248 nm or more and 355 nm or less. The light emitting element has a polygonal shape having a side of 1 μm or more and 100 μm or less, a circular shape having a diameter of 1 μm or more and 100 μm or less, or an elliptical shape having a major axis of more than 1 μm and 100 μm or less and a minor axis of 1 μm or more and less than 100 μm. Item 2. The source substrate structure according to any one of Items 17 to 21.