Element transfer method, and element transfer device

Abstract

To provide an element transfer method capable of transferring an element with high precision and reliability while preventing elements from falling off and remaining on a stamp by reducing the adhesive force during transfer of the element compared to when picking up the same with a simple configuration, and an element transfer device.SOLUTION: The transfer method of an element 10 for transferring an element to a target board from a stamp includes the following steps: aligning the position of a target board 2 and an element picked up by the adhesive force of the stamp 3; partially supplying energy to an elastic member 31 for controlling the vibration range connected to the stamp from energy supply units 100 and 90 in a state that the target board and the stamp are brought relatively close together, and the elements of the target board and the stamp are in contact; and relatively separating the target board and the stamp while applying vibration to the stamp and the stamp element through a hemispherical member 81 and an elastic member by a vibration unit 80.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a device transfer method and a device transfer apparatus. [Background technology]

[0002] In recent years, the use of light has been explored in the fields of high-speed communication, large-capacity communication, and sensing. In particular, a technology called "silicon photonics," which fabricates optical circuits on silicon substrates using the complementary metal oxide semiconductor (CMOS) process, similar to semiconductor electronic circuits, has attracted attention. Optical circuits fabricated using silicon photonics are microscopic circuits with optical control functions, including optical input / output sections and optical modulators. These components are interconnected by submicron-order fine optical waveguides. Normally, to operate an optical circuit, light from a light source such as a laser diode (LD) must be precisely connected to the optical input section via an external transmission medium such as an optical fiber. However, by directly placing the LD chip or optical element itself on an optical circuit substrate and optically connecting it, it is possible to operate the optical circuit with less space and fewer components.

[0003] Another device that requires the placement of microchips is a microLED display. Conventionally, when manufacturing a microLED display, multiple microLEDs formed by dividing a wafer are placed one by one on a circuit board using a pick-and-place process. This manufacturing method requires the pick-and-place process to be repeated tens of thousands of times, which is time-consuming and increases manufacturing costs.

[0004] Patent Document 1 discloses a method for transferring multiple elements to a target substrate in a single pick-and-place process using a temporary holding member such as an adhesive stamp, thereby shortening the time required for the process and reducing manufacturing costs.

[0005] However, if the adhesive strength of such a holding member for holding the element is weak, the held element may fall off the holding member, preventing the element from being transferred to the desired position on the target substrate, resulting in operational malfunction. Therefore, the holding member is required to have strong adhesive strength for holding the element. On the other hand, if the adhesive strength of the holding member for holding the element is too strong, the held element will not be transferred to the target substrate and will remain held by the holding member. This will prevent the element from being transferred to the desired position on the target substrate, resulting in operational malfunction. Furthermore, if the pick-and-place process is carried out with the element remaining on the holding member, the element on the substrate will collide with the element remaining on the holding member, resulting in damage to the element.

[0006] Therefore, Patent Document 1 also discloses a method for facilitating the transfer of elements by plasma treatment of the contact surface of the element with the target substrate, or a method for facilitating the transfer of elements by reducing the adhesive strength of the holding member by heat treatment. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 6453437 Summary of the Invention [Problem to be solved by the invention]

[0008] However, the conventional technology disclosed in Patent Document 1 requires an expensive device for generating plasma, and the optical element may fall off during plasma processing. Furthermore, because the entire optical element, holding member, and target substrate are heated during the heat treatment, misalignment due to differences in their respective thermal expansion coefficients may occur, resulting in failure to transfer to the desired position. In other words, relative misalignment between the element and the target substrate may occur. Furthermore, because the holding member is heated, deterioration of the holding member may occur during the heat treatment cycle.

[0009] A non-limiting example of the present disclosure aims to provide an element transfer method and element transfer device that has a simple configuration and that prevents elements from falling off or remaining on the stamp by reducing the adhesive force during element transfer compared to when the elements are picked up, and that can achieve highly accurate and reliable element transfer. [Means for solving the problem]

[0010] A method for transferring elements according to one aspect of the present disclosure includes aligning the positions of a target substrate and an element picked up by the adhesive force of a stamp, bringing the target substrate and the stamp relatively close to each other so that the target substrate and the element on the stamp are in contact with each other, an energy supply unit partially supplies energy to an elastic member for controlling a vibration reaching range connected to the stamp; The stamp and the elements of the stamp are vibrated by a vibration unit via a hemispherical member and the elastic member while the target substrate and the stamp are spaced apart relative to each other, thereby transferring the elements from the stamp to the target substrate.

[0011] An element transfer apparatus according to one aspect of the present disclosure includes: a target substrate placement stage on which a target substrate is placed; a stamp head having a stamp capable of picking up an element by adhesive force; an elastic member for controlling a vibration reaching range that disperses and transmits vibration to the stamp; a frame that holds the stamp head so that the stamp can face the target substrate placement table; a substrate position adjustment mechanism that can adjust the position of the target substrate with respect to the stamp and move the target substrate and the stamp closer to or farther from each other; an imaging unit that captures images of the element and the target substrate to detect a positional misalignment between the element and the target substrate; a contact detection unit that detects contact between the element and the target substrate; a vibration unit disposed above the elastic member to apply vibration to the stamp and the elements of the stamp; a hemispherical member that disperses vibrations caused by the vibration unit; an energy supplying unit that partially supplies energy to the elastic member; an energy supply unit adjustment mechanism that adjusts the energy supply position relative to the elastic member; a control unit that controls the substrate position adjustment mechanism to reduce the amount of positional misalignment, controls the substrate position adjustment mechanism to bring the target substrate and the stamp relatively closer together, controls the energy supply unit to partially supply the energy to an elastic member in a state in which the target substrate and the elements of the stamp are in contact with each other based on the detection by the contact detection unit, controls the vibration unit to impart vibration to the stamp and the elements of the stamp while controlling a vibration reachable range, and controls the substrate position adjustment mechanism to transfer the elements from the stamp to the target substrate by relatively separating the target substrate and the stamp while imparting vibration to the stamp and the elements of the stamp by the vibration unit; Equipped with. [Effects of the Invention]

[0012] According to the above aspects of the present disclosure, it is possible to provide an element transfer method and element transfer device that have a simple configuration including a vibration unit that applies vibration to an element and a stamp via an elastic member, and an energy supply unit that supplies energy for partial heating or cooling to the elastic member, and that partially changes the elastic modulus of the elastic member by partial energy supply, thereby controlling the vibration reach range and vibrating the element, and that reduces the adhesive force when the element is transferred compared to when it was picked up, thereby preventing the element from falling off or remaining on the stamp and achieving highly accurate and reliable element transfer. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram illustrating a configuration example of an element transfer device according to a first embodiment of the present disclosure. [Figure 2] 1 is a diagram illustrating a stamp head, a vibration unit, and an energy supply unit of an element transfer device according to an embodiment of the present disclosure. [Figure 3] 1 is a flowchart illustrating a device transfer method according to an embodiment of the present disclosure. [Figure 4A] 1 is a diagram for explaining a method for transferring an element according to an embodiment of the present disclosure; [Figure 4B] 1 is a diagram for explaining a method for transferring an element according to an embodiment of the present disclosure; [Figure 4C] 1 is a diagram for explaining a method for transferring an element according to an embodiment of the present disclosure; [Figure 4D] 1 is a diagram for explaining a method for transferring an element according to an embodiment of the present disclosure; [Figure 4E] 1 is a diagram for explaining a method for transferring an element according to an embodiment of the present disclosure; [Figure 4F] 1 is a diagram for explaining a method for transferring an element according to an embodiment of the present disclosure; [Figure 4G] 1 is a diagram for explaining a method for transferring an element according to an embodiment of the present disclosure; [Figure 4H] 1 is a diagram for explaining a method for transferring an element according to an embodiment of the present disclosure; [Figure 5A] FIG. 1 is a diagram for explaining the effect of energy supply according to the first embodiment of the present disclosure. [Figure 5B] FIG. 1 is a diagram for explaining the effect of energy supply according to the first embodiment of the present disclosure. [Figure 6] FIG. 10 is a diagram illustrating a configuration example of an element transfer device according to a second embodiment of the present disclosure. [Figure 7] 1 is a flowchart illustrating a device transfer method according to a second embodiment of the present disclosure. [Figure 8A] FIG. 10 is a diagram illustrating the effect of cooling the elastic member according to the second embodiment of the present disclosure. [Figure 8B] FIG. 10 is a diagram illustrating the effect of cooling the elastic member according to the second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0014] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0015] In this specification and drawings, components having substantially the same functions are designated by the same reference numerals, and redundant explanations are omitted. In the following drawings, the shapes, thicknesses, lengths, etc. of the components shown in each figure may differ from the actual shapes, thicknesses, lengths, etc. of the components due to the creation of the drawings. Furthermore, the materials of each component are not limited to those described in this embodiment.

[0016] In Figure 1 and subsequent figures, the X-axis direction, Y-axis direction, and Z-axis direction represent directions parallel to the X-axis, Y-axis, and Z-axis, respectively. The X-axis direction and Y-axis direction are perpendicular to each other. The X-axis direction and Z-axis direction are perpendicular to each other. The Y-axis direction and Z-axis direction are perpendicular to each other. The XY plane represents an imaginary plane parallel to the X-axis direction and Y-axis direction. The XZ plane represents an imaginary plane parallel to the X-axis direction and Z-axis direction. The YZ plane represents an imaginary plane parallel to the Y-axis direction and Z-axis direction. Also, in Figure 1 and subsequent figures, the direction indicated by the arrow in the X-axis direction is the positive X-axis direction, and the direction opposite to this direction is the negative X-axis direction. Also, in Figure 1 and subsequent figures, the direction indicated by the arrow in the Y-axis direction is the positive Y-axis direction, and the direction opposite to this direction is the negative Y-axis direction. Also, in Figure 1 and subsequent figures, the direction indicated by the arrow in the Z-axis direction is the positive Z-axis direction, and the direction opposite to this direction is the negative Z-axis direction. The Z-axis direction is, for example, equivalent to the vertical direction or up-down direction, and the X-axis direction and the Y-axis direction are, for example, equivalent to the horizontal direction or left-right direction.

[0017] [Embodiment 1] <Element transfer device> First, an element transfer apparatus D1 according to an embodiment of the present disclosure will be described with reference to Figures 1 and 2. Figure 1 is a diagram showing an example of the configuration of the element transfer apparatus D1 according to an embodiment of the present disclosure, and Figure 2 is a diagram showing the stamp head 30, vibration unit 80, and energy supply unit 90 of the element transfer apparatus D1 according to the embodiment of the present disclosure.

[0018] The element transfer device D1 includes at least a source substrate mounting table 11, a target substrate mounting table 21, a stamp head 30, an elastic member 31, a frame 40, a substrate position adjustment mechanism 51, an imaging unit 60, an imaging unit adjustment mechanism 61, a contact detection unit 70, a vibration unit 80, a hemispherical member 81, an energy supply unit 90, an energy supply unit adjustment mechanism 91, and a control unit C1. The element transfer device D1 picks up elements 10 from a source substrate 1 by the adhesive force of a stamp 3, reduces the adhesive force, and then transfers the elements 10 from the stamp 3 to a target substrate 2.

[0019] The source substrate setting stage 11 is, for example, a rectangular plate-shaped stage on which the source substrate 1 is set. The type of source substrate setting stage 11 is not limited as long as it is capable of setting the source substrate 1. For example, the source substrate setting stage 11 may be provided with suction holes for adsorbing the source substrate 1, and the source substrate 1 may be tightly attached to the source substrate setting stage 11 by applying negative pressure to the suction holes.

[0020] Here, the source substrate 1 is, for example, a rectangular plate-shaped member, and the elements 10 are formed on its surface. The elements 10 are, for example, optical elements formed on the source substrate 1 by a CMOS process. The elements 10 may be formed by any method that can achieve the desired performance. Alignment marks may be formed on the source substrate 1 and the elements 10 for the purpose of aligning the stamp 3 and the elements 10 when they are picked up from the source substrate 1 by the stamp 3.

[0021] The target substrate mounting stage 21 is, for example, a rectangular plate-shaped stage on which the target substrate 2 is mounted. The type of target substrate mounting stage 21 is not limited as long as it is capable of mounting the target substrate 2. The target substrate mounting stage 21 may be provided with suction holes for adsorbing the target substrate 2, for example, and the target substrate 2 may be brought into close contact with the target substrate mounting stage 21 by applying negative pressure to the suction holes.

[0022] Here, the target substrate 2 is, for example, a rectangular plate-shaped member, and is a substrate onto whose surface the elements 10 formed on the source substrate 1 are transferred. The target substrate 2 may have an electric circuit or an optical circuit (not shown) formed thereon so that desired performance can be obtained when the elements 10 are transferred. The target substrate 2 may have an alignment mark for the purpose of aligning the elements 10 with the target substrate 2 when the elements 10 are picked up from the source substrate 1 and transferred.

[0023] The stamp head 30 is, for example, a rectangular plate-shaped base that is held on the underside of a through-hole 40a in the center of the top plate 40b of the frame 40 and that holds the stamp 3. As shown in Fig. 2, the stamp head 30 may be of any type as long as it can hold a stamp 3 that has, for example, a T-shaped side, in other words, a rectangular plate-shaped stamp 3 with the central portion 3a protruding downward in the shape of a rectangular plate. The stamp head 30 may be provided with, for example, suction holes for adsorbing the stamp 3, and the stamp 3 may be brought into close contact with the stamp head 30 by applying negative pressure to the suction holes.

[0024] Here, the stamp 3 has viscoelasticity and is a member that uses its viscoelasticity, i.e., adhesive force, to pick up the elements 10 formed on the source substrate 1 with the central portion 3a of the stamp 3 and transfer the elements 10 to the desired positions on the target substrate 2. The stamp 3 is made of viscoelastic material such as silicone rubber. Any type of stamp 3 may be used as long as it has viscoelasticity. However, by making the stamp 3 transparent, the positions of the stamp 3 and the elements 10, or the positions of the elements 10 picked up by the stamp 3 and the target substrate 2, can be simultaneously observed from above in the Z-axis direction when capturing an image with the imaging unit 60 (described later). The stamp 3 may have a convex structure, such as the protruding central portion 3a, on the surface facing the elements 10, with the same size as the elements 10 in the X-axis and Y-axis directions. This prevents other elements formed on the source substrate 1 from being picked up when the elements 10 come into contact with the stamp 3. The size of the convex structure of the stamp 3 is not limited to be the same as that of the element 10 in the X-axis and Y-axis directions, but may be larger than that of the element 10 in the X-axis and Y-axis directions, or may be smaller than that of the element 10 in the X-axis and Y-axis directions. By making the size of the convex structure of the stamp 3 in the Z-axis direction at least twice the size of the element 10 in the Z-axis direction, it is possible to easily prevent pickup of other elements when the element 10 and the stamp 3 come into contact with each other.

[0025] The elastic member 31 is disposed on the upper surface of the contact detection unit 70 in the Z-axis direction and is a member for transmitting vibrations applied by the vibration unit 80 to the stamp 3. The elastic member 31 is made of elastic epoxy resin, silicone resin, or the like. The elastic member 31 may be of any type as long as it has elasticity. However, by making the elastic member 31 transparent, when capturing an image with the imaging unit 60 (described later), the positions of the stamp 3 and the element 10, or the positions of the element 10 picked up by the stamp 3 and the target substrate 2, can be simultaneously observed from above in the Z-axis direction. The thickness of the elastic member 31 is appropriately selected depending on the dimensions of the element 10 and the materials of the element 10 and the target substrate 2, but is 100 μm to 10 mm. Furthermore, the elastic modulus of the elastic member 31 is appropriately selected depending on the dimensions of the element 10 and the materials of the element 10 and the target substrate 2, but if the elastic modulus of the elastic member 31 is too large (for example, the elastic modulus exceeds 10 [MPa]), the element 10 may be damaged by vibrations caused by the vibration unit 80, which will be described later. Therefore, the elastic modulus of the elastic member 31 is set to be 0.5 [MPa] or more and 10 [MPa] or less, at which elastic deformation is easy.

[0026] The frame 40 is a downward C-shaped member, and holds the stamp head 30 at a position below the through-hole 40a in the center of the top plate 40b. An imaging unit 60, which will be described later, is disposed above the through-hole 40a in the frame 40, and by using the imaging unit 60 to capture an image of the stamp head 30 side below the through-hole 40a, it is possible to observe the relative positions of the stamp 3 and the elements 10, or the relative positions of the elements 10 picked up by the stamp 3 and the target substrate 2, from above in the Z-axis direction. The frame 40 is made of a material such as stainless steel.

[0027] The substrate stage 50 is a platform disposed below the top plate 40b of the frame 40, and is supported by a substrate position adjustment mechanism 51. A source substrate mounting table 11 and a target substrate mounting table 21 are placed on the upper surface of the substrate stage 50. The substrate stage 50 may be integral with the source substrate mounting table 11 and the target substrate mounting table 21, or the source substrate mounting table 11 and the target substrate mounting table 21 may be fixed to the substrate stage 50 as separate members using screws or the like.

[0028] The substrate position adjustment mechanism 51 is a movable stage for adjusting the position of the substrate stage 50 in the X-axis, Y-axis, and Z-axis directions. Specifically, the substrate position adjustment mechanism 51 can adjust the position of the substrate stage 50 in the X-axis and Y-axis directions so that the relative positions of the elements 10 of the source substrate 1 placed on the source substrate setting table 11 on the substrate stage 50 and the stamp 3 in the X-axis and Y-axis directions roughly match during pickup. Furthermore, the substrate position adjustment mechanism 51 can adjust the position of the substrate stage 50 in the X-axis and Y-axis directions so that the relative positions of the target substrate 2 placed on the target substrate setting table 21 on the substrate stage 50 and the elements 10 picked up by the stamp 3 in the X-axis and Y-axis directions roughly match during transfer. Furthermore, the substrate position adjustment mechanism 51 controls the position of the substrate stage 50 in the Z-axis direction so that the elements 10 of the source substrate 1 placed on the source substrate setting table 11 on the substrate stage 50 and the stamp 3 come into contact with and separate from each other during pickup, allowing for a pickup operation. Furthermore, the substrate position adjustment mechanism 51 controls the position of the substrate stage 50 in the Z-axis direction so that the target substrate 2 placed on the target substrate setting table 21 on the substrate stage 50 and the elements 10 picked up by the stamp 3 can come into contact with and separate from each other during transfer, thereby enabling the transfer operation. The substrate position adjustment mechanism 51 is realized by combining, for example, a linear stage using a linear ball guide, a gonio stage, and the like.

[0029] An imaging unit 60, which will be described later, is used to detect positional misalignment during position adjustment of the substrate stage 50. The substrate position adjustment mechanism 51 is configured to be movable in at least four mutually different axial directions. The four axial directions include the X-axis direction, the Y-axis direction, and the Z-axis direction, as well as a rotational direction around the Z-axis. This allows for fine movements in each step of the element transfer method, which will be described later, thereby improving transfer accuracy and achieving high-quality transfer. The substrate position adjustment mechanism 51 may be movable in six directions: the X-axis direction, the Y-axis direction, the Z-axis direction, and the rotational directions around each of these axes. The substrate position adjustment mechanism 51 is provided with a motor (not shown) and an encoder (not shown), and position information detected by the encoder (not shown) is input to the control unit C1.

[0030] The imaging unit 60 is disposed above the through-hole 40a of the frame 40 in the vertical direction, and is a unit that captures images of the stamp 3 and the elements 10 on the source substrate 1, as well as the elements 10 picked up by the stamp 3 and the target substrate 2, thereby making it possible to detect the amount of misalignment between the stamp 3 and the elements 10 on the source substrate 1, and the amount of misalignment between the elements 10 picked up by the stamp 3 and the target substrate 2. The imaging unit 60 is composed of, for example, a lens and a camera, and information captured by the camera is input to the control unit C1, and the amount of misalignment is calculated by a calculation unit C2 of the control unit C1.

[0031] The imaging unit adjustment mechanism 61 is a movable stage for adjusting the position of the imaging unit 60. Specifically, the imaging unit 60 is adjusted to a position where the stamp 3 and the elements 10 on the source substrate 1 can be observed by the imaging unit 60 during pickup, and the elements 10 picked up by the stamp 3 and the target substrate 2 can be observed by the imaging unit 60 during transfer. The imaging unit adjustment mechanism 61 is realized by combining, for example, a linear motion stage using a linear ball guide. The imaging unit adjustment mechanism 61 is configured to be movable in at least three mutually different axial directions. The three axial directions include the X-axis direction, the Y-axis direction, and the Z-axis direction. The imaging unit adjustment mechanism 61 is provided with a motor and an encoder (not shown), and position information detected by the encoder (not shown) is input to the control unit C1.

[0032] As shown in FIG. 2, the contact detection unit 70 is a sensor disposed between the stamp head 30 and the elastic member 31 and detects contact of the stamp 3. Specifically, for example, it detects contact between the stamp 3 and the elements 10 on the source substrate 1 during pickup, and contact between the elements 10 picked up by the stamp 3 and the target substrate 2 during transfer. The contact detection unit 70 is, for example, a piezoelectric force sensor. Voltage and force information measured by the contact detection unit 70 is input to the control unit C1. By monitoring the force information detected by the contact detection unit 70 with the control unit C1, the position of the substrate stage 50 in the Z-axis direction can be adjusted, and the control unit C1 can detect excessive pressure being applied to the elements 10, thereby preventing damage to the elements 10.

[0033] As shown in FIG. 2 , the vibration unit 80 is disposed in contact with the upper surface of the elastic member 31 and applies vibrations to the stamp 3 via the elastic member 31 and the contact detector 70. Specifically, when the substrate position adjustment mechanism 51 separates the elements 10 picked up by the stamp 3 from the target substrate 2 in the Z-axis direction during transfer, the vibrations are applied to the stamp 3 and the elements 10 picked up by the stamp 3 via the hemispherical member 81 and the elastic member 31 (described later). In a range where the vibration frequency of the vibration unit 80 is low (e.g., a range where the frequency is less than 10 Hz), the vibrations are absorbed because the elastic member 31 and the stamp 3 are viscoelastic. On the other hand, in a range where the vibration frequency of the vibration unit 80 is too high (e.g., a range where the frequency is more than 100 kHz), the elastic member 31 and the stamp 3 are heated by the vibrations, which may cause material deterioration. Furthermore, in a region where the amplitude of the vibrations generated by the vibration unit 80 is small (e.g., a region where the amplitude is less than 10 nm), the vibrations are absorbed by the elastic member 31 and the stamp 3, which are made of a viscoelastic material, and do not reach the element 10. On the other hand, in a region where the amplitude of the vibrations generated by the vibration unit 80 is large (e.g., a region where the amplitude is more than 50 μm), the vibrations may damage the element 10. Therefore, the vibration unit 80 generates any vibrations, for example, with a frequency of 10 Hz to 100 kHz and an amplitude of 10 nm to 50 μm, and is, for example, an actuator using a piezoelectric element that utilizes the piezoelectric effect. The vibration unit 80 is configured to generate vibrations in the Z-axis direction, i.e., the vibration direction C shown in FIG. 2. The vibration unit 80 is controlled by a control unit C1 to apply vibrations to the stamp 3 and the element 10 of the stamp 3.

[0034] As shown in FIG. 2, the hemispherical member 81 is disposed on the underside of the vibration unit 80 in the Z-axis direction, and is a member that distributes vibrations to the stamp 3 through contact with a portion of the elastic member 31 near the center. Because the hemispherical member 81 is hemispherical, it can distribute the vibrations in the Z-axis direction generated by the vibration unit 80 in the X-axis direction and the Y-axis direction, i.e., vibration directions A and B shown in FIG. 2. The material of the hemispherical member 81 is not particularly limited as long as it can distribute the vibrations generated by the vibration unit 80 within the elastic member 31. The material of the hemispherical member 81 is, for example, epoxy resin, acrylic resin, or metal, and is processed into a hemispherical shape by molding or cutting.

[0035] The energy supply unit 90 is a unit that partially supplies thermal energy to the elastic member 31. The energy supply unit 90 is, for example, an infrared laser, and has an infrared wavelength of 800 [nm] to 1 [mm]. The energy supply unit 90 may be configured with a combination of galvanometer mirrors in order to control the position of the energy partially supplied to the elastic member 31, or the position of the energy partially supplied to the elastic member 31 may be controlled by an energy supply unit adjustment mechanism 91, which will be described later. The energy supply unit 90 is controlled by the control unit C1 so as to partially supply thermal energy to the elastic member 31.

[0036] The energy supply unit adjustment mechanism 91 is a movable stage for adjusting the position of the energy supply unit 90 in the X-axis direction, the Y-axis direction, and the Z-axis direction. The energy supply unit adjustment mechanism 91 is realized by combining, for example, a linear motion stage using a linear ball guide. The energy supply unit adjustment mechanism 91 is configured to be movable in at least three mutually different axial directions. The three axial directions include the X-axis direction, the Y-axis direction, and the Z-axis direction. The energy supply unit adjustment mechanism 91 is provided with a motor and an encoder (not shown), and position information detected by the encoder (not shown) is input to the control unit C1.

[0037] The control unit C1 is a microcomputer or the like that controls the operation of the components that make up the element transfer apparatus D1, and includes a calculation unit C2 that performs various calculations, such as calculating the amount of misalignment from imaged information. The control unit C1 controls the image capture unit adjustment mechanism 61 so that, by capturing images with the image capture unit 60, the stamp 3 and the elements 10 on the source substrate 1 can be observed during pickup, and the elements 10 picked up by the stamp 3 and the target substrate 2 can be observed during transfer. The control unit C1 also controls the substrate position adjustment mechanism 51 so that the amount of misalignment in the X-axis and Y-axis directions between the stamp 3 and the elements 10 detected by the image capture unit 60 during pickup, and the amount of misalignment in the X-axis and Y-axis directions between the elements 10 picked up by the stamp 3 and the target substrate 2 during transfer, each approach as close to zero as possible. Furthermore, the control unit C1 detects contact between the stamp 3 and the elements 10 on the source substrate 1 during pickup and contact between the elements 10 picked up by the stamp 3 and the target substrate 2 during transfer, based on force information detected by the contact detection unit 70, and controls the substrate position adjustment mechanism 51, respectively. Furthermore, when the control unit C1 detects contact between the elements 10 picked up by the stamp 3 during transfer and the target substrate 2, the control unit C1 controls the energy supply unit 90 to supply energy to the elastic member 31, and controls the position of the energy supply unit 90 using the energy supply unit adjustment mechanism 91. Furthermore, when the control unit C1 supplies thermal energy to the elastic member 31 partially, rather than entirely, using the energy supply unit 90 during transfer, the control unit C1 controls the vibration unit 80 to apply vibration to the stamp 3 and the elements 10 on the stamp 3.

[0038] <Element transfer method> Next, the transfer method of the element 10 is carried out at least in the following steps S101 to S105.

[0039] First, in step S101, the control unit C1 controls the operation of the substrate position adjusting mechanism 51 based on the information captured by the imaging unit 60, and aligns the positions of the elements 10 on the source substrate 1 and the stamp 3 (corresponding to step S10 below).

[0040] Next, in step S102, the control unit C1 controls the operation of the substrate position adjustment mechanism 51 to move the source substrate 1 and the stamp 3 relatively closer to or farther apart, and the element 10 is picked up by the stamp 3 using the adhesive force of the stamp 3 (corresponding to steps S20, S21, and S30 below).

[0041] Next, in step S103, the control unit C1 controls the operation of the substrate position adjusting mechanism 51 based on the information captured by the imaging unit 60, and aligns the positions of the target substrate 2 and the elements 10 on the stamp 3 (corresponding to step S40 below).

[0042] Next, in step S104, the control unit C1 controls the operation of the substrate position adjusting mechanism 51 to bring the target substrate 2 and the stamp 3 relatively close to each other, so that the elements 10 of the stamp 3 come into contact with the target substrate 2 (corresponding to steps S50 and S51 below).

[0043] Next, in step S105, with thermal energy supplied to the elastic member 31 by the energy supply unit 90, the vibration unit 80 applies vibration to the stamp 3 and the element 10 on the stamp 3, while the control unit C1 controls the operation of the substrate position adjustment mechanism 51 to move the target substrate 2 and stamp 3 relatively apart and transfer the element 10 from the stamp 3 to the target substrate 2 (corresponding to steps S60, S70, and S80 below).

[0044] These steps are described in more detail below.

[0045] A method for transferring an element according to an embodiment of the present disclosure using element transfer apparatus D1 will be described with reference to Figures 3, 4A, 4B, 4C, 4D, 4E, 4F, 4G, and 4H. Figure 3 is a flowchart illustrating the method for transferring an element according to an embodiment of the present disclosure, and Figures 4A, 4B, 4C, 4D, 4E, 4F, 4G, and 4H are diagrams for explaining the method for transferring an element according to an embodiment of the present disclosure.

[0046] 4A, an alignment operation between the element 10 and the stamp 3 is performed (step S10). In step S10, the source substrate 1 is placed on the source substrate placement stage 11, and the target substrate 2 is placed on the target substrate placement stage 21.

[0047] Here, the alignment operation refers to controlling the operation of the substrate position adjustment mechanism 51 by the control unit C1 to move the substrate stage 50 to a predetermined position in the XY plane. In step S10, the predetermined position refers to, for example, a position of the substrate stage 50 where the positions of the elements 10 on the source substrate 1 and the stamp 3 on the XY plane are aligned. Here, the alignment of the elements 10 and the stamp 3 means that their alignment marks are aligned or their outlines are aligned. Therefore, in step S10, the imaging unit 60 images the elements 10 and the stamp 3 on the source substrate 1, and the calculation unit C2 calculates and detects the amount of misalignment between the elements 10 and the stamp 3 on the source substrate 1 relative to the predetermined position based on the image information. Based on the detected amount of misalignment, the substrate position adjustment mechanism 51 adjusts the position of the substrate stage 50 under the control of the control unit C1 so as to reduce the amount of misalignment. By adjusting the position of the substrate stage 50, the position of the source substrate 1 and the position of the elements 10 on the source substrate 1 are adjusted. Furthermore, if the position of the imaging unit 60 needs to be adjusted, the position of the imaging unit 60 may be adjusted by the imaging unit adjustment mechanism 61 under the control of the control unit C1. The position adjustment accuracy of the substrate position adjustment mechanism 51 in the operation of step S10 is on the order of nanometers. Note that the accuracy of the position adjustment in the operation of step S10 is not limited to the order of nanometers, and may be performed to be on the order of micrometers. Figure 4A shows the state after the alignment operation of the element 10 and the stamp 3 is completed.

[0048] Next, as shown in FIG. 4B, the substrate stage 50 is raised (step S20). The substrate position adjustment mechanism 51 is used to raise the substrate stage 50 under the control of the controller C1. As the substrate stage 50 rises, the distance in the Z-axis direction between the elements 10 on the source substrate 1 and the stamp 3 decreases. After the substrate stage 50 starts to rise, if the controller C1 determines based on the detection information from the contact detector 70 that the contact detector 70 has not detected contact between the elements 10 and the stamp 3 (step S21, NO), the controller C1 controls the substrate position adjustment mechanism 51 to continue raising the substrate stage 50. If the controller C1 determines based on the detection information from the contact detector 70 that the contact detector 70 has detected contact between the elements 10 and the stamp 3 (step S21, YES), the controller C1 controls the substrate position adjustment mechanism 51 to stop raising the substrate stage 50.

[0049] Here, the threshold value used by the contact detector 70 to determine contact is appropriately set depending on the physical properties and shapes of the element 10 and the stamp 3. For example, if a piezoelectric force sensor is used for the contact detector 70, the threshold value used to determine contact is 1 nN to 10 N. In step S20, the substrate position adjustment mechanism 51 raises the substrate stage 50 at a speed of, for example, 1 nm / sec to 1000 μm / sec under the control of the controller C1. Note that by lowering the threshold value used by the contact detector 70 to determine contact or by slowing the raising speed of the substrate stage 50, excessive elevation of the substrate stage 50 can be suppressed, thereby preventing damage to the element 10. FIG. 4B shows a state in which the substrate stage 50 has been raised and the element 10 has come into contact with the stamp 3.

[0050] Next, as shown in FIG. 4C, the substrate stage 50 is lowered (step S30). The substrate position adjustment mechanism 51 is used under the control of the controller C1 to lower the substrate stage 50. With the elements 10 and the stamp 3 in contact with each other, the substrate stage 50 is lowered under the control of the controller C1. The elements 10 are peeled off from the source substrate 1 by the adhesive force of the stamp 3 and picked up by the stamp 3. The adhesive force of the stamp 3 is appropriately selected depending on the physical properties of the elements 10 and the target substrate 2 (described later). In step S30, the speed at which the substrate stage 50 is lowered by the substrate position adjustment mechanism 51 under the control of the controller C1 is, for example, 10 μm / sec to 1000 mm / sec. It is known that the adhesive force of a viscoelastic material such as the stamp 3 increases depending on the peeling speed in a certain speed range. Therefore, the faster the speed at which the substrate stage 50 descends while the element 10 and the stamp 3 are in contact, the stronger the adhesive strength of the stamp 3 becomes, and the stronger the force that peels the element 10 from the source substrate 1. In other words, the element 10 can be easily picked up by the stamp 3. FIG. 4C shows the state in which the substrate stage 50, which had been raised, is lowered after contact between the element 10 and the stamp 3 is detected.

[0051] Next, as shown in FIG. 4D, an alignment operation between the elements 10 and the target substrate 2 is performed (step S40). Here, the alignment operation refers to the control unit C1 controlling the operation of the substrate position adjustment mechanism 51 to move the substrate stage 50 to a predetermined position in the XY plane. In step S40, the predetermined position refers to, for example, a position of the substrate stage 50 where the positions of the target substrate 2 and the elements 10 picked up by the stamp 3 coincide in the XY plane. Here, the alignment of the positions of the target substrate 2 and the elements 10 means that their alignment marks coincide with each other or their outer shapes coincide with each other. Therefore, in step S40, the imaging unit 60 images the target substrate 2 and the elements 10 picked up by the stamp 3, and the calculation unit C2 calculates and detects the amount of positional misalignment between the target substrate 2 and the elements 10 picked up by the stamp 3 relative to the predetermined position based on the image information. Based on the detected amount of positional misalignment, the substrate position adjustment mechanism 51 adjusts the position of the substrate stage 50 under the control of the control unit C1 so as to reduce the amount of positional misalignment. The position of the target substrate 2 is adjusted by adjusting the position of the substrate stage 50. Furthermore, if adjustment of the position of the imaging unit 60 is necessary, the position of the imaging unit 60 may be adjusted by the imaging unit adjustment mechanism 61 under the control of the control unit C1. The position adjustment accuracy of the substrate position adjustment mechanism 51 in the operation of step S40 is on the order of nanometers. Note that the accuracy of the position adjustment in the operation of step S40 is not limited to the order of nanometers, and may be performed to be on the order of micrometers. Figure 4D shows the state after the alignment operation of the target substrate 2 and the element 10 picked up by the stamp 3 is completed.

[0052] Next, as shown in FIG. 4E, the substrate stage 50 is raised (step S50). As the substrate stage 50 rises, the distance in the Z-axis direction between the target substrate 2 and the element 10 picked up by the stamp 3 decreases. After the substrate stage 50 starts to rise, if the control unit C1 determines based on the detection information from the contact detection unit 70 that the contact detection unit 70 has not detected contact between the target substrate 2 and the element 10 picked up by the stamp 3 (step S51, NO), the substrate stage 50 continues to rise under the control of the substrate position adjustment mechanism 51. If the control unit C1 determines based on the detection information from the contact detection unit 70 that the contact detection unit 70 has detected contact between the target substrate 2 and the element 10 picked up by the stamp 3 (step S51, YES), the substrate position adjustment mechanism 51 stops the rise of the substrate stage 50 under the control of the control unit C1. The threshold value for determining contact by the contact detection unit 70 is appropriately set based on the mechanical properties and shapes of the target substrate 2, the stamp 3, and the element 10. For example, if a piezoelectric force sensor is used for the contact detection unit 70, the threshold for determining contact is 1 nN to 10 N. In step S50, the substrate position adjustment mechanism 51 raises the substrate stage 50 at a speed of, for example, 1 nm / sec to 1000 μm / sec. By lowering the threshold for determining contact in the contact detection unit 70 or slowing down the raising speed of the substrate stage 50, excessive elevation of the substrate stage 50 can be suppressed, thereby preventing damage to the elements 10. FIG. 4E shows a state in which the substrate stage 50 has risen and the elements 10 picked up by the stamp 3 have come into contact with the target substrate 2. Here, the state in which the elements 10 picked up by the stamp 3 have come into contact with the target substrate 2 refers to a state in which the amount of pressing of the elements 10 into and held in contact with the target substrate 2 is greater than the amplitude of vibration in the Z-axis direction (described below), preventing the elements 10 from detaching from the target substrate 2 even when vibration is applied. Under such dimensional relationships, as an example, when the amplitude of vibration by the vibration unit 80 is 10 [nm] to 10 [μm], the amount by which the element 10 is pressed into the target substrate 2 via the stamp 3 is, for example, 1 [μm] to 50 [μm].Furthermore, by making the amount by which the element 10 is pressed into the target substrate 2 through the stamp 3 smaller than the dimension in the Z-axis direction of the convex structure of the stamp 3, contamination of the target substrate 2 or the stamp 3 caused by parts of the stamp 3 other than the convex structure coming into contact with the target substrate 2 can be prevented.

[0053] Next, with the target substrate 2 and the elements 10 picked up by the stamp 3 in contact with each other, the energy supplier 90 starts to partially supply thermal energy to a part of the elastic member 31, as shown in FIG. 4F (step S60).

[0054] Here, with reference to FIGS. 5A and 5B, the effect of energy supply according to the first embodiment of the present disclosure using the element transfer apparatus D1 will be described. FIGS. 5A and 5B are diagrams for explaining the effect of energy supply according to the first embodiment of the present disclosure. As shown in FIG. 5A, thermal energy is supplied to an energy supply position 90a of the elastic member 31 located above the central portion 3a of the stamp 3 in the Z-axis direction. The energy supply positions 90a of the elastic member 31 are two strip-shaped regions sandwiching a narrow strip-shaped region 90b above the rectangular central portion 3a of the stamp 3 that corresponds to the rectangular shape of the element 10. As a specific example, the two strip-shaped regions sandwich the narrow strip-shaped region 90b above the rectangular central portion 3a of the stamp 3, among three regions divided by a dividing line along the X-axis direction parallel to the length direction of the larger aspect ratio of the outer shape of the element 10 (for example, the direction along the long side of a rectangle or the long axis of an ellipse).

[0055] Although thermal energy is supplied to each of the two energy supply positions 90a in this example, thermal energy may be supplied to either one of the energy supply positions 90a.

[0056] 5B, when thermal energy is supplied to each of the two energy supply positions 90a of the elastic member 31, as indicated by arrows 901 parallel to the Y-axis direction in FIG. 5A, the temperature of the elastic member 31 rises locally at the positions of the elastic member 31 corresponding to the energy supply positions 90a of the elastic member 31, causing a partial decrease in the elastic modulus of the elastic member 31. When the elastic modulus of the elastic member 31 is partially decreased, when vibrations applied by the vibration unit 80 (described later) are dispersed within the elastic member 31, the energy supply positions 90a with the decreased elastic modulus are more likely to absorb the vibrations, thereby reducing the Y-axis component of the vibrations reaching the stamp 3 and the element 10. In other words, by partially supplying thermal energy to the elastic member 31 by the energy supply unit 90, the vibrations reaching the stamp 3 and the element 10 by the vibration unit 80 can be controlled. The temperature change of the elastic member 31 due to the thermal energy supplied by the energy supply unit 90 is controlled within a range from room temperature to the heat-resistant limit temperature of the elastic member 31. Therefore, the temperature change of the elastic member 31 due to the thermal energy supplied by the energy supply unit 90 is, for example, 20°C to 100°C. When the temperature of the elastic member 31 falls below room temperature, for example, 20°C, due to the thermal energy supplied by the energy supply unit 90, this is defined as cooling, and will be explained in the second embodiment described below. Also, when the temperature of the elastic member 31 rises above the heat-resistant limit temperature, for example, 100°C, due to the thermal energy supplied by the energy supply unit 90, the elastic member 31 deteriorates, causing breakage or the like.

[0057] Here, the position of the energy supply unit 90 that supplies thermal energy to the elastic member 31 is controlled by an energy supply unit adjustment mechanism 91. Fig. 4F shows a state in which thermal energy is partially supplied to the elastic member 31 by the energy supply unit 90 after contact between the target substrate 2 and the element 10 of the stamp 3 is detected.

[0058] Next, with thermal energy partially supplied to the elastic member 31 by the energy supply unit 90, the vibration unit 80 starts vibrating the elastic member 31, the stamp 3, and the elements 10 of the stamp 3, as shown in FIG. 4G (step S70). When the vibration unit 80 applies vibration in the Z-axis direction, i.e., vibration direction C shown in FIG. 2, the vibration is dispersed within the elastic member 31 via the hemispherical member 81 in the X-axis direction and the Y-axis direction, i.e., vibration directions A and B shown in FIG. 2. The dispersed vibration is transmitted to the stamp 3 and the elements 10 of the stamp 3, and shear stress acts at the interface between the target substrate 2 and the elements 10. The adhesive force acting at the interface between the stamp 3 and the elements 10 is primarily due to van der Waals forces. However, van der Waals bonds are more easily broken by applying shear forces acting in lateral directions, such as the horizontal directions (i.e., the X-axis and Y-axis directions), than by tensile forces acting in the vertical direction (i.e., the Z-axis direction). Therefore, even if the force acting on the target substrate 2 and the elements 10 is weak when the substrate stage 50 is lowered in step S80 (described later) to relatively separate the target substrate 2 and the stamp 3, the vibration unit 80 can apply vibration to the stamp 3 and the elements 10 of the stamp 3 via the hemispherical member 81 and the elastic member 31, thereby breaking the van der Waals bonds formed at the interface between the stamp 3 and the elements 10, and thus the elements 10 can be reliably transferred to the target substrate 2 with reduced adhesive force. Furthermore, by providing the hemispherical member 81 and the elastic member 31, even if the vibration direction of the vibration unit 80 is only the Z-axis direction, i.e., the vibration direction C shown in FIG. 2, vibrations can be applied to the stamp 3 and the elements 10 of the stamp 3 in the X-axis direction, Y-axis direction, and Z-axis direction, i.e., in the three-axis directions of vibration A, vibration B, and vibration C shown in FIG. 2. Furthermore, since the vibration directions transmitted to the stamp 3 and the element 10 of the stamp 3 are the X-axis direction, the Y-axis direction, and the Z-axis direction, i.e., all of vibration directions A, B, and C shown in Figure 2, the stress generated at the interface between the stamp 3 and the element 10 can be made into a splitting stress, thereby locally reducing the adhesive force and enabling the element 10 to be stably and easily transferred to the target substrate 2.Furthermore, in a region where the vibration frequency of the vibration unit 80 is low (for example, a region where the frequency is less than 10 Hz), the elastic member 31 and the stamp 3 are viscoelastic, and therefore the vibrations are absorbed. On the other hand, in a region where the vibration frequency of the vibration unit 80 is too high (for example, a region where the frequency is greater than 100 kHz), the elastic member 31 and the stamp 3 are heated by the vibration, which may cause material deterioration. Therefore, the vibration frequency of the vibration unit 80 should be 10 Hz to 100 kHz, and preferably, a frequency of 500 Hz to 50 kHz is used to more stably obtain the effect of stress control by the vibration, and the element 10 can be reliably transferred to the target substrate 2. Furthermore, in a region where the vibration amplitude of the vibration unit 80 is low (for example, a region where the amplitude is less than 10 nm), the vibrations are absorbed because the elastic member 31 and the stamp 3 are viscoelastic, and therefore do not reach the element 10. On the other hand, in a region where the amplitude of the vibration by the vibration unit 80 is large (for example, a region where the amplitude exceeds 50 μm), the vibration may damage the element 10. Therefore, the amplitude of the vibration by the vibration unit 80 may be 10 nm to 50 μm, and preferably, by setting the amplitude to 10 nm to 10 μm, the effect of stress control by the vibration can be obtained more stably, and the element 10 can be reliably transferred to the target substrate 2.

[0059] The vibration generated by the vibration unit 80 is appropriately set according to the shape of the element 10. Specifically, the adhesive force can be more easily reduced by increasing the amplitude in the X-axis direction or the Y-axis direction parallel to the length direction of the outer shape of the element 10 where the aspect ratio is large (e.g., the direction along the long side of a rectangle or the long axis of an ellipse) compared to the amplitude in the Y-axis direction or the X-axis direction parallel to the length direction of the outer shape of the element 10 where the aspect ratio is small (e.g., the direction along the short side of a rectangle or the short axis of an ellipse). This is because the elastic deformation of the stamp 3 is greater in the length direction of the outer shape of the element 10 than in the length direction of the outer shape of the element 10 where the aspect ratio is small, and the amplitude of the vibration is more absorbed by the stamp 3, thereby reducing the shear force generated at the interface between the stamp 3 and the element 10. When increasing the amplitude, it is preferable to increase it by at least about 10% in order to practically exert the adhesive force reduction effect. It is more preferable to increase it by at least the aspect ratio of the outer shape of the element 10, i.e., by 200% or more if the aspect ratio is 2. Therefore, it is preferable that the rate of decrease in the elastic modulus of the elastic member 31 due to the thermal energy supplied by the energy supply unit 90 is at least about 10%, and it is more preferable that the elastic modulus is 50% or less if it is equal to or greater than the aspect ratio of the external shape of the element 10, i.e., if the aspect ratio is 2.

[0060] Next, as shown in FIG. 4H, the substrate stage 50 is lowered (step S80). Under the control of the controller C1, the substrate stage 50 is lowered while the picked-up elements 10 are in contact with the target substrate 2 and the stamp 3, and while the vibration unit 80 is vibrating the stamp 3 and the elements 10 on the stamp 3. By this, the elements 10 are peeled off from the stamp 3 due to the adhesive force between the target substrate 2 and the elements 10, and transferred to the target substrate 2. In step S80, the substrate position adjustment mechanism 51 lowers the substrate stage 50 at a speed of, for example, 1 nm / sec to 100 μm / sec. It is known that the adhesive force of a viscoelastic material such as the stamp 3 increases depending on the peeling speed within a certain speed range. Therefore, the slower the speed at which the substrate stage 50 is lowered while the elements 10 on the stamp 3 are in contact with the target substrate 2, the weaker the adhesive force of the stamp 3 and the force with which the stamp 3 can hold the elements 10. However, since the effect of the descent speed is limited, in steps S60 and S70, the vibration unit 80 vibrates the stamp 3 and elements 10 of the stamp 3 while the energy supply unit 90 is partially supplying thermal energy to the elastic member 31, thereby reducing the adhesive force acting on the stamp 3 and elements 10, thereby enabling reliable transfer even when the force acting on the target substrate 2 and elements 10 is weak. Figure 4H shows the state in which the raised substrate stage 50 has been lowered while the vibration unit 80 is vibrating the stamp 3 and elements 10 of the stamp 3.

[0061] By the above steps, the transfer of the element 10 is achieved.

[0062] As described above, in the transfer of elements 10, in steps S60 and S70, thermal energy is partially supplied to elastic member 31 by energy supply unit 90, causing the elastic modulus to be partially reduced, and then vibration unit 80 applies vibrations to stamp 3 and elements 10 on stamp 3 in vibration directions A, B, and C shown in FIG. 2 . This makes it easier for the regions with reduced elastic modulus to absorb vibrations, reducing the Y-axis component or X-axis component of the vibration that reaches stamp 3 and elements 10. In other words, by partially supplying thermal energy to elastic member 31 by energy supply unit 90, vibration unit 80 can control the vibration that reaches stamp 3 and elements 10, thereby controlling the stress at the interface between stamp 3 and elements 10 on stamp 3 and reducing the adhesive force acting on stamp 3 and elements 10 on stamp 3, allowing elements 10 to be reliably transferred to target substrate 2.

[0063] [Embodiment 2] Hereinafter, a second embodiment of the present disclosure will be described with reference to the drawings. In the following description, differences from the first embodiment will be mainly described, and descriptions of commonalities will be omitted or simplified as appropriate.

[0064] An element transfer apparatus D2 according to the second embodiment of the present disclosure will be described with reference to Fig. 6. Fig. 6 is a diagram illustrating an example of the configuration of the element transfer apparatus D2 according to the second embodiment of the present disclosure.

[0065] The element transfer device D2 in embodiment 2 has a cooling unit 100 as another energy supply unit instead of the energy supply unit 90, and has a cooling unit adjustment mechanism 101 as another energy supply unit adjustment mechanism instead of the energy supply unit adjustment mechanism 91.

[0066] The cooling unit 100 is a unit that locally cools the elastic member 31. The cooling unit 100 is, for example, a Peltier element that locally cools the elastic member 31 by being in partial contact with the elastic member 31. The cooling unit 100 may be any device that can locally cool the elastic member 31, and may also be an injector that injects cooled air through a tube.

[0067] The temperature change of the elastic member 31 cooled by the cooling unit 100 is controlled within a range from room temperature to not exceeding the glass transition temperature of the elastic member 31. Therefore, the cooling temperature of the cooling unit 100 is -60°C to 20°C. If the temperature of the elastic member 31 cooled by the cooling unit 100 falls below the glass transition temperature, for example, -60°C, the elastic member 31 loses its elasticity and becomes a hard glass state. If the temperature of the elastic member 31 cooled by the cooling unit 100 exceeds room temperature, for example, 20°C, this is defined as heating, and will be described in the first embodiment.

[0068] The cooling unit 100 is controlled by the control unit C1 so as to locally cool the elastic member 31. The cooling unit 100 may also include a cooling unit adjustment mechanism 101 for the purpose of controlling the cooling position of the elastic member 31.

[0069] The cooling unit adjustment mechanism 101 is a movable stage for adjusting the position of the cooling unit 100 in the X-axis, Y-axis, and Z-axis directions. The cooling unit adjustment mechanism 101 is realized by combining, for example, a linear motion stage using a linear ball guide. The cooling unit adjustment mechanism 101 is configured to be movable in at least three mutually different axial directions. The three axial directions include the X-axis, Y-axis, and Z-axis directions. The cooling unit adjustment mechanism 101 is provided with a motor and an encoder (not shown), and position information detected by the encoder (not shown) is input to the control unit C1.

[0070] Here, a method for transferring an element using element transfer apparatus D2 according to embodiment 2 will be described with reference to Figures 7, 8A, and 8B. Figure 7 is a flowchart illustrating the method for transferring an element according to embodiment 2 of the present disclosure, and Figures 8A and 8B are diagrams for explaining the effect of cooling the elastic member according to embodiment 2 of the present disclosure.

[0071] Steps S101, S102, S103, and S104 are the same as those in the first embodiment.

[0072] Next, in step S106, with the elastic member 31 partially cooled by the cooling section 100, vibration is applied to the stamp 3 and the element 10 on the stamp 3 by the vibration unit 80, while the control section C1 controls the operation of the substrate position adjustment mechanism 51 to move the target substrate 2 and the stamp 3 relatively apart, thereby transferring the element 10 from the stamp 3 to the target substrate 2 (corresponding to steps S61, S70, and S80 below).

[0073] Steps S70 and S80 are the same as those in the first embodiment.

[0074] With the target substrate 2 and the element 10 picked up by the stamp 3 in contact with each other, the cooling unit 100 starts local cooling of the elastic member 31 (step S61). Specifically, as shown in FIG. 8A, the cooling unit 100 cools a cooling position 100a of the elastic member 31 located above the central portion 3a of the stamp 3 in the Z-axis direction. The cooling position 100a of the elastic member 31 is a narrow strip-like region above the rectangular central portion 3a of the stamp 3 that corresponds to the rectangular shape of the element 10. As a specific example, the cooling position 100a is a narrow strip-like region above the rectangular central portion 3a of the stamp 3, one of three regions divided by a dividing line along the X-axis direction parallel to the length direction of the outer shape of the element 10 with the largest aspect ratio (for example, the direction along the long side of a rectangle or the long axis of an ellipse).

[0075] 8B, when the elastic member 31 is locally cooled in the direction of arrow 902 parallel to the Y-axis in FIG. 8A, the temperature of the elastic member 31 locally drops at a position on the elastic member 31 corresponding to the cooling position 100a of the elastic member 31, and the elastic modulus of the elastic member 31 partially increases. When the elastic modulus of the elastic member 31 increases, when the vibration applied by the vibration unit 80 in step S70 is dispersed within the elastic member 31, the vibration is more easily transmitted at the cooling position 100a where the elastic modulus has increased, and the X-axis component of the vibration reaching the stamp 3 and the element 10 increases. In other words, by locally cooling the elastic member 31 with the cooling unit 100, the vibration reaching the stamp 3 and the element 10 can be controlled by the vibration unit 80. The cooling temperature of the cooling unit 100 is -60°C to 20°C.

[0076] Here, the position of the cooling unit 100 that locally cools the elastic member 31 is controlled by a cooling unit adjustment mechanism 101.

[0077] More specifically, the adhesive force can be more easily reduced by increasing the amplitude in the X-axis direction or the Y-axis direction parallel to the length direction of the outer shape of element 10 where the aspect ratio is large (e.g., the direction along the long side of a rectangle or the long axis of an ellipse) compared to the amplitude in the Y-axis direction or the X-axis direction parallel to the length direction of the outer shape of element 10 where the aspect ratio is small (e.g., the direction along the short side of a rectangle or the short axis of an ellipse). This is because the elastic deformation of stamp 3 is greater in the length direction of the outer shape of element 10 than in the length direction of the outer shape of element 10 where the aspect ratio is small, and the amplitude of the vibration is more absorbed by stamp 3, thereby reducing the shear force generated at the interface between stamp 3 and element 10. When increasing the amplitude, it is preferable to increase it by at least about 10% in order to practically exert the adhesive force reduction effect, and it is more preferable to increase it by at least the aspect ratio of the outer shape of element 10, i.e., if the aspect ratio is 2, it is more preferable to increase it by 200% or more. Therefore, it is preferable that the rate of increase in the elastic modulus of the elastic member 31 when the elastic member 31 is cooled by the cooling section 100 is at least about 10%, and it is more preferable that the elastic modulus is equal to or greater than the aspect ratio of the external shape of the element 10, i.e., if the aspect ratio is 2, the elastic modulus is equal to or greater than 200%.

[0078] According to the second embodiment, as described above, in the transfer of elements 10, the cooling unit 100 locally cools the elastic member 31 in steps S61 and S70 to partially increase the elastic modulus, and then the vibration unit 80 applies vibrations to the stamp 3 and elements 10 on the stamp 3 in vibration directions A, B, and C shown in FIG. 2 . This makes it easier for vibrations to be transmitted in the region with increased elastic modulus, and increases the Y-axis component or the X-axis component of the vibration that reaches the stamp 3 and elements 10. In other words, by partially cooling the elastic member 31 with the cooling unit 100, the vibration that reaches the stamp 3 and elements 10 can be controlled by the vibration unit 80, which controls the stress at the interface between the stamp 3 and elements 10 on the stamp 3, and thereby enables elements 10 to be reliably transferred to the target substrate 2 in a state where the adhesive force acting on the stamp 3 and elements 10 on the stamp 3 is reduced.

[0079] It is also possible to provide a device with two functions, that is, the thermal energy supply of the embodiment and the cooling of the second embodiment, and to perform both functions.

[0080] Therefore, in the first or second embodiment, neither plasma treatment nor heat treatment is required, and a simple configuration including a vibration unit 80 and an energy supply unit 90 or a cooling unit 100 is used. By reducing the adhesive force when transferring the element 10 compared to when it was picked up, it is possible to prevent the element 10 from falling off or remaining on the stamp 3, and to achieve high-quality, i.e., high-precision and reliable, transfer of the element 10 to the target substrate 2.

[0081] It should be noted that any of the various embodiments or modifications described above can be appropriately combined to achieve the effects of each. In addition, combinations of embodiments, combinations of examples, or combinations of embodiments and examples are possible, and combinations of features from different embodiments or examples are also possible.

[0082] Although the present disclosure has been fully described in connection with the preferred embodiments with reference to the accompanying drawings, various changes or modifications will be apparent to those skilled in the art. Such changes or modifications should be understood to be included within the scope of the present disclosure as defined by the appended claims, unless they depart therefrom. Furthermore, changes in the combination or order of elements in the embodiments may be made without departing from the scope and spirit of the present disclosure.

[0083] (Addendum) The above description of the embodiments discloses the following techniques.

[0084] (Technology 1) The positions of a target substrate and an element picked up by the adhesive force of a stamp are aligned, and the target substrate and the stamp are brought relatively close to each other so that the target substrate and the element on the stamp are in contact with each other. an energy supply unit partially supplies energy to an elastic member for controlling a vibration reaching range connected to the stamp; A method for transferring an element, comprising: vibrating the stamp and the element of the stamp via a hemispherical member and the elastic member using a vibration unit while relatively separating the target substrate and the stamp, thereby transferring the element from the stamp to the target substrate.

[0085] (Technology 2) A method for transferring elements according to Technology 1, in which, prior to the alignment, a source substrate having the elements and the stamp are brought relatively close to and separated from each other, and the elements of the source substrate are picked up by the stamp using the adhesive force of the stamp.

[0086] (Technology 3) The method for transferring an element described in Technology 1 or 2, wherein the supply of energy to the elastic member by the energy supply unit is heating of the elastic member, and the energy supply position is a position on the elastic member excluding above the element and a position excluding above along the length direction of the outer shape of the element with a large aspect ratio.

[0087] (Technology 4) A method for transferring an element described in any one of Technologies 1 to 3, wherein the supply of energy to the elastic member by the energy supply unit is to cool the elastic member, and the energy supply position is a position above the element on the elastic member and above along the length direction in which the aspect ratio of the outer shape of the element is large.

[0088] (Technology 5) A method for transferring elements described in any one of Technologies 1 to 4, wherein the vibration unit generates vibrations in the Z-axis direction as the up-and-down direction of the stamp and the elements of the stamp in mutually orthogonal X, Y and Z axis directions, disperses the vibrations within the hemispherical member and the elastic member, and transfers the elements to the target substrate by relatively separating the target substrate and the stamp while applying vibrations to the stamp and the elements of the stamp in all directions, including the X-axis direction, the Y-axis direction and the Z-axis direction.

[0089] (Technology 6) The element transfer method according to Technology 5, wherein the amplitude of vibration by the vibration unit is smaller than the amount of pressing when the target substrate and the stamp are brought relatively close to each other and the element is pressed into contact with the target substrate to be transferred.

[0090] (Technology 7) The element transfer method according to any one of Technologies 1 to 6, wherein the vibration by the vibration unit has a frequency of 10 Hz to 100 kHz and an amplitude of 10 nm to 50 μm. (Technology 8) A target substrate setting table on which a target substrate is set; a stamp head having a stamp capable of picking up an element by adhesive force; an elastic member for controlling a vibration reaching range that disperses and transmits vibration to the stamp; a frame that holds the stamp head so that the stamp can face the target substrate placement table; a substrate position adjustment mechanism that can adjust the position of the target substrate with respect to the stamp and move the target substrate and the stamp closer to or farther from each other; an imaging unit that captures images of the element and the target substrate to detect a positional misalignment between the element and the target substrate; a contact detection unit that detects contact between the element and the target substrate; a vibration unit disposed above the elastic member to apply vibration to the stamp and the elements of the stamp; a hemispherical member that disperses vibrations caused by the vibration unit; an energy supplying unit that partially supplies energy to the elastic member; an energy supply unit adjustment mechanism that adjusts the energy supply position relative to the elastic member; a control unit that controls the substrate position adjustment mechanism to reduce the amount of positional misalignment, controls the substrate position adjustment mechanism to bring the target substrate and the stamp relatively closer together, controls the energy supply unit to partially supply the energy to an elastic member in a state in which the target substrate and the elements of the stamp are in contact with each other based on the detection by the contact detection unit, controls the vibration unit to impart vibration to the stamp and the elements of the stamp while controlling a vibration reachable range, and controls the substrate position adjustment mechanism to transfer the elements from the stamp to the target substrate by relatively separating the target substrate and the stamp while imparting vibration to the stamp and the elements of the stamp by the vibration unit; An element transfer device comprising:

[0091] (Technology 9) The present invention further includes a source substrate mounting stage for mounting a source substrate on which the element is formed, the frame holds the stamp head so that the stamp can face the source substrate placement table; the substrate position adjustment mechanism is capable of adjusting a position of the source substrate with respect to the stamp and of moving the source substrate and the stamp toward and away from each other; the contact detection unit detects contact between the element and the source substrate; The device transfer apparatus according to technology 8, wherein the control unit controls the substrate position adjustment mechanism to move the source substrate and the stamp relatively closer to and farther from each other, so that the device is picked up by the stamp using the adhesive force of the stamp.

[0092] (Technology 10) An element transfer device according to Technology 8 or 9, wherein the energy supply unit is a heating means, and the energy supply position is a position on the elastic member excluding the position above the element and excluding the position above along the length direction of the outer shape of the element with a large aspect ratio.

[0093] (Technology 11) An element transfer device according to any one of Technologies 8 to 10, wherein the energy supply unit is a cooling means, and the energy supply position is a position above the element on the elastic member and above along the length direction in which the aspect ratio of the outer shape of the element is large.

[0094] (Technology 12) An element transfer device described in any one of Technologies 8 to 11, wherein the control unit controls the vibration unit to generate vibration in the Z-axis direction as the up-and-down direction of the stamp and the elements of the stamp in mutually perpendicular X, Y, and Z-axis directions, and distributes the vibration within the hemispherical member and the elastic member, applying vibration to the stamp and the elements of the stamp in all directions along the X-axis, Y-axis, and Z-axis, and then relatively separating the target substrate and the stamp, thereby transferring the elements to the target substrate.

[0095] (Technology 13) An element transfer device according to Technology 12, wherein the vibration unit has an amplitude smaller than the amount of pressing when the target substrate and the stamp are brought relatively close to each other to press the element into contact with the target substrate and transfer it.

[0096] (Technology 14) The element transfer device according to any one of Technologies 8 to 13, wherein the vibration unit generates any vibration having a frequency of 10 Hz to 100 kHz and an amplitude of 10 nm to 50 μm.

[0097] Each of these configurations provides a simple configuration that includes a vibration unit that applies vibration to the element and stamp via the elastic member, and an energy supply unit that supplies energy for partial heating or cooling to the elastic member, thereby partially changing the elastic modulus of the elastic member through partial energy supply, thereby controlling the vibration reach range and vibrating the element.By reducing the adhesive force when the element is transferred compared to when it was picked up, it is possible to provide an element transfer method and element transfer device that can prevent the element from falling off or remaining on the stamp and achieve highly accurate and reliable element transfer. [Industrial Applicability]

[0098] An embodiment of the present disclosure can be suitably used for an element transfer method and an element transfer apparatus. Furthermore, the element transfer method and element transfer apparatus according to the above aspect of the present disclosure can transfer, for example, optical elements to a target substrate with high accuracy, and therefore can be applied in fields such as micro LED displays, high-speed optical communications typified by silicon photonics, and high-accuracy sensing using laser light. [Explanation of symbols]

[0099] 1 Source Board 2 Target board 3 Stamps 3a central part 10 elements 11 Source board installation stand 21 Target board installation stand 30 Stamp Head 31 Elastic member 40 frames 40a through hole 40b Top plate 50 Substrate Stage 51 Board position adjustment mechanism 60 Imaging unit 61 Imaging unit adjustment mechanism 70 Contact detection unit 80 vibration unit 81 Hemispherical member 90 Energy Supply Department 90a Energy supply location 91 Energy supply adjustment mechanism 100 Cooling section 100a cooling position 101 Cooling section adjustment mechanism C1 control section C2 calculation section D1, D2 element transfer device

Claims

1. The positions of a target substrate and an element picked up by the adhesive force of a stamp are aligned, and the target substrate and the stamp are brought relatively close to each other so that the target substrate and the element on the stamp are in contact with each other. an energy supply unit partially supplies energy to an elastic member for controlling a vibration reaching range connected to the stamp; A method for transferring an element, comprising: vibrating the stamp and the element of the stamp via a hemispherical member and the elastic member using a vibration unit while relatively separating the target substrate and the stamp, thereby transferring the element from the stamp to the target substrate.

2. The element transfer method according to claim 1 , further comprising the steps of: before the alignment, bringing a source substrate having the elements and the stamp relatively close to and farther from each other, and picking up the elements of the source substrate onto the stamp by the adhesive force of the stamp.

3. 2. The element transfer method according to claim 1, wherein the energy supply unit supplies energy to the elastic member by heating the elastic member, and the energy supply position is a position on the elastic member excluding an upper portion of the element and a position excluding an upper portion along a length direction in which an aspect ratio of the outer shape of the element is large.

4. 2. The element transfer method according to claim 1, wherein the supply of energy to the elastic member by the energy supply unit is to cool the elastic member, and the energy supply position is a position above the element on the elastic member and above along the length direction in which the aspect ratio of the outer shape of the element is large.

5. 2. The element transfer method according to claim 1, wherein the vibration unit generates vibrations in the Z-axis direction as a vertical direction of the stamp and the elements of the stamp in mutually orthogonal X, Y and Z axis directions, and distributes the vibrations within the hemispherical member and the elastic member to apply vibrations to the stamp and the elements of the stamp in all directions, including the X-axis direction, the Y-axis direction and the Z-axis direction, while relatively separating the target substrate and the stamp, thereby transferring the elements to the target substrate.

6. 6. The element transfer method according to claim 5, wherein the amplitude of vibration by the vibration unit is smaller than the amount of pressing when the target substrate and the stamp are brought relatively close to each other and the element is pressed into contact with the target substrate to be transferred.

7. 7. The element transferring method according to claim 1, wherein the vibration by the vibration unit has a frequency of 10 Hz to 100 kHz and an amplitude of 10 nm to 50 μm.

8. a target substrate placement table on which a target substrate is placed; a stamp head having a stamp capable of picking up an element by adhesive force; an elastic member for controlling a vibration reaching range that disperses and transmits vibration to the stamp; a frame that holds the stamp head so that the stamp can face the target substrate placement table; a substrate position adjustment mechanism that can adjust the position of the target substrate with respect to the stamp and move the target substrate and the stamp closer to or farther from each other; an imaging unit that captures images of the element and the target substrate to detect a positional misalignment between the element and the target substrate; a contact detection unit that detects contact between the element and the target substrate; a vibration unit disposed above the elastic member to apply vibration to the stamp and the elements of the stamp; a hemispherical member that disperses vibrations caused by the vibration unit; an energy supplying unit that partially supplies energy to the elastic member; an energy supply unit adjustment mechanism that adjusts the energy supply position relative to the elastic member; a control unit that controls the substrate position adjustment mechanism to reduce the amount of positional misalignment, controls the substrate position adjustment mechanism to bring the target substrate and the stamp relatively closer together, controls the energy supply unit to partially supply the energy to an elastic member in a state in which the target substrate and the elements of the stamp are in contact with each other based on the detection by the contact detection unit, controls the vibration unit to impart vibration to the stamp and the elements of the stamp while controlling a vibration reachable range, and controls the substrate position adjustment mechanism to transfer the elements from the stamp to the target substrate by relatively separating the target substrate and the stamp while imparting vibration to the stamp and the elements of the stamp by the vibration unit; An element transfer device comprising:

9. a source substrate mounting stage on which the source substrate on which the device is formed is mounted; the frame holds the stamp head so that the stamp can face the source substrate placement table; the substrate position adjustment mechanism is capable of adjusting a position of the source substrate with respect to the stamp and of moving the source substrate and the stamp toward and away from each other; the contact detection unit detects contact between the element and the source substrate; The device transfer apparatus according to claim 8 , wherein the control unit controls the substrate position adjustment mechanism to move the source substrate and the stamp relatively closer to and farther from each other, so that the device is picked up by the stamp by the adhesive force of the stamp.

10. 9. The element transfer device according to claim 8, wherein the energy supply unit is a heating means, and the energy supply position is a position on the elastic member excluding an upper portion of the element and a position excluding an upper portion along a length direction in which an aspect ratio of the outer shape of the element is large.

11. 9. The element transfer device according to claim 8, wherein the energy supply unit is a cooling means, and the energy supply position is a position above the element on the elastic member and above along a length direction in which an aspect ratio of the outer shape of the element is large.

12. 9. The element transfer device according to claim 8, wherein the control unit controls the vibration unit to generate vibrations in the Z-axis direction as the up-and-down direction of the stamp and the elements of the stamp in mutually orthogonal X, Y and Z axis directions, and distributes the vibrations within the hemispherical member and the elastic member to apply vibrations to the stamp and the elements of the stamp in all directions, including the X-axis direction, the Y-axis direction and the Z-axis direction, and then the target substrate and the stamp are spaced apart relative to each other, thereby transferring the elements to the target substrate.

13. 13. The element transfer device according to claim 12, wherein the vibration unit has an amplitude smaller than a pressing amount when the target substrate and the stamp are brought relatively close to each other to press the element into contact with the target substrate and transfer the element.

14. 14. The element transfer device according to claim 8, wherein the vibration unit generates any vibration having a frequency of 10 Hz to 100 kHz and an amplitude of 10 nm to 50 μm.

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