Stamp component for transferring microstructures, convex part, transfer method, manufacturing method of electric equipment, manufacturing method of electronic equipment, manufacturing method of LED display

Abstract

To provide stamp components for microstructure transfer that can optimize the temporary bonding force on the surface of silicone rubber film stamps in a short time.SOLUTION: A stamp component for microstructure transfer is characterized in that a silicone rubber film is formed on a substrate, and the silicone rubber film surface on the opposite side of the substrate has one or more recesses that are closed except for the surface opening.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a stamp component for transferring a micro-structure by a stamping method.

Background Art

[0002] In recent years, with the miniaturization of semiconductor elements, a micro-structure transfer technology using a stamp has attracted attention as an assembly means for electrical and electronic application products using semiconductor elements (Non-Patent Document 1). In particular, by using this technology to transfer one, or a plurality, or even a large number of tens of thousands of mini-LEDs (LEDs with a short side of 100 μm or more to several 100 μm) or micro-LEDs (LEDs with a short side of 100 μm or less, and further 50 μm or less) at a time, the development of technologies for manufacturing displays for signage, TVs, medical use, in-vehicle, pads, smartphones, smartwatches, etc., and LED displays for AR / VR, etc. has become active.

[0003] With the miniaturization and thinning of semiconductor chips and various electrical and electronic elements, in semiconductor mounting and the assembly of electronic devices, instead of the conventional transfer of elements using vacuum adsorption, the transfer of micro-structures using a stamp is being attempted. For example, various fine elements such as various high-performance LSI / IC chips, minute resistors, capacitors, inductors, SAW filter elements, and MEMS chips such as acceleration sensors become transfer objects.

[0004] Thus, the transfer of micro-structures using a stamp has grown into an essential technology for manufacturing devices that will enrich and diversify our future lives.

[0005] It has been reported that a rubber stamp mainly composed of silicone such as PDMS (polydimethylsiloxane) can be used for the adhesive layer used in the stamping method to transport a large number of elements from a supply substrate to a receiving substrate (Patent Document 1). As a more practical form, a stamp structure adapted and evolved for a chip mounting device is shown in Patent Document 2.

[0006] FIG. 20 shows an explanatory diagram of the structure of an example of a stamp component for transferring a micro-structure of the prior art. Using FIG. 20, the structure and features of an example of a conventional stamp shown in Patent Document 2 will be briefly described. In FIG. 20, 41 is a quartz substrate, and 42 is a silicone rubber film. 43 is a silicone rubber film, and 44 to 48 are convex portions made of a silicone rubber film provided on the surface of the silicone rubber film 43.

[0007] FIG. 20(a) is a flat stamp 200 in which a silicone rubber film 42 is formed on a quartz substrate 41, and is used for transferring a plurality or a large number of micro-structures at once. FIGS. 20(b) to (f) show that a silicone rubber film 43 is formed on a quartz substrate 41. Convex portions 44 to 48 are provided on the surface of the silicone rubber film 43 on the side opposite to the quartz substrate 41. The stamp 200 provided with these convex portions is used when transferring one or a plurality of transfer objects.

[0008] The transfer object is temporarily adhered to the surface of the silicone rubber film 42 or the uppermost surface of the convex portions of the convex portions 44 to 48 by the pressure-sensitive adhesive force of the silicone rubber, moved to a predetermined position and brought into contact with the placement destination, and then the silicone rubber surface is peeled off from the transfer object and placed at the predetermined position. For example, by disposing a resin or the like having an adhesive force stronger than the temporary adhesive force of the silicone rubber film surface on the surface of the predetermined placement destination, the transfer object is received on the surface of the predetermined placement destination, and the surface of the silicone rubber film 42 or the uppermost surface of the convex portions of the convex portions 44 to 48 can be peeled off from the transfer object. At that time, the temporary adhesive force of the silicone rubber film surface that determines the transfer ability is mainly the pressure-sensitive adhesive force, and depends on the hardness, surface adhesion, tackiness, etc. of the silicone rubber film. Therefore, the physical properties of the silicone rubber film must be adjusted and optimized to meet the requirements from the characteristics of the transfer object such as size, surface morphology, weight, etc., or the process conditions such as the transfer speed and acceleration of the transfer device.

Prior Art Documents

Patent Documents

[0009] [Patent Document 1] U.S. Patent No. 7,943,491 Specification [Patent Document 2] Japanese Unexamined Patent Application Publication No. 2020 - 129638 [Non - Patent Document]

[0010] [Non - Patent Document 1] Matthew A. Meitl, Zheng - Tao Zhu, Vipan Kumar, Keon Jae Lee, Xue Feng, Yonggang Y. Huang, Ilesanmi Adesida, Ralph G. Nuzzo & John A. Rogers, ”Transfer printing by kinetic control of adhesion to an elastomeric stamp”, Nature Materials Volume 5, 33 - 38 (2006). [Summary of the Invention] [Problems to be Solved by the Invention]

[0011] However, in the above - described configuration, when optimizing the temporary adhesive force on the surface of the silicone rubber film stamp, it is very difficult and time - consuming to optimize the physical property adjustment of the silicone rubber film that meets the requirements from the transfer object and transfer conditions, and there is also a problem that it cannot be optimized in some cases.

[0012] The present invention has been made to solve the above problems, and an object thereof is to provide a stamp component for transferring microstructures that can optimize the temporary adhesive force on the surface of a silicone rubber film stamp in a short time. [Means for Solving the Problems]

[0013] In order to solve the above problems, in the first invention of the present invention, a silicone rubber film is formed on a substrate, and the surface of the silicone rubber film on the side opposite to the substrate has one or more recesses with the surface openings closed, and a stamp component for transferring a micro-structure is provided.

[0014] In this way, by using a silicone rubber film with a pressure-sensitive adhesive force greater than the required temporary adhesive force and forming one or more closed recesses on its surface, it is possible to adjust in the direction of reducing the surface area of contact between the micro-structure, which is the object to be transferred, and the silicone rubber film. As a result, it is not necessary to perform a delicate optimization of the pressure-sensitive adhesive force (depending on the hardness, surface adhesion, tackiness, etc. of the silicone rubber) through synthetic optimization for changing the physical properties of the silicone rubber film. Instead, it becomes possible to optimize the temporary adhesive force of the surface in contact with the micro-structure by design changes that optimize the shape, opening area (size and number), and layout of the closed recesses. That is, according to the first invention of the present invention, it is possible to provide a stamp component for transferring a micro-structure that can optimize the temporary adhesive force of the surface of the silicone rubber film stamp in a short time. Further, when using the stamp component of the present invention, not only a single micro-structure but also a plurality or a large number of micro-structures can be transferred at once.

[0015] Also, in this way, when the surface of the silicone rubber film including the closed recess and the micro-structure are temporarily adhered, the closed recess becomes a closed space. Since it is pressure-bonded with an optimized pressing amount during temporary adhesion, the closed space of the closed recess is in a decompressed state at the stage of temporary adhesion. As a result, when the volume of the concave space is small, although weak, an attractive force acts on the micro-structure, so that the adhesion state can be stabilized.

[0016] The shape of the surface opening of the closed recess can be, for example, a shape selected from the group consisting of a circle, an ellipse, a ring, and a polygon.

[0017] The shape of the surface opening of the closed recess can be any shape as long as it is a closed shape.

[0018] It is preferable that the depth of the closed recess does not reach the substrate.

[0019] By doing so, since the silicone rubber film and the substrate are adhesively fixed over the entire surface, the durability is improved. As a result, the replacement frequency of the stamp component of the present invention can be reduced, and thus the productivity of the transfer of the microstructures can be improved.

[0020] A plurality of the closed recesses may be arranged in a matrix on the surface of the silicone rubber film.

[0021] By doing so, the microstructure and the silicone rubber surface including the closed recess can be adhesively held with a uniform force within the temporary adhesion surface.

[0022] A plurality of the closed recesses may be arranged in a geometric pattern on the surface of the silicone rubber film.

[0023] By doing so, it is possible to form closed recesses with an optimal layout according to the shape of the temporary adhesion surface of the microstructure which is the adherend.

[0024] The portion of the surface of the silicone rubber film other than the closed recesses may have a lattice pattern.

[0025] By doing so, a large recess surface opening can be formed. Therefore, even when using a silicone rubber having a very strong pressure-sensitive adhesive force or particularly a very strong adhesive force, by optimizing the opening area (size and number) of the recesses, it can be optimized to exhibit a desired relatively weak temporary adhesive force.

[0026] The portion of the surface of the silicone rubber film other than the closed recesses may have a cross-sectional pattern of a honeycomb structure.

[0027] Also in this case, similar to the lattice pattern, since the surface to which the microstructures are temporarily adhered has a regular layout, a temporary adhesion force is uniformly generated on the temporary adhesion surface of the microstructures. As a result, a stable transfer operation can be provided.

[0028] On the surface of the silicone rubber film, the closed recess may include at least an annular recess.

[0029] By doing so, when temporarily adhering a micro-structure having a surface with good symmetry such as a square or a circle, a stable temporary adhesion force can be exerted.

[0030] The closed recess may include a first closed recess and a second closed recess having different surface opening areas from each other, and the surface opening area of the second closed recess may be smaller than the surface opening area of the first closed recess.

[0031] By doing so, the adhesion area with the micro-structure can be controlled by both the first closed recess and the second closed recess having a surface opening area smaller than that of the first closed recess. That is, the adhesion force can be roughly adjusted by the relatively large first closed recess, and the adhesion area and the adhesion force can be finely adjusted by the second closed recess having a surface opening area smaller than that of the first closed recess. Further, when the opening depth of the second closed recess having a surface opening area smaller than that of the first closed recess is minute, in the closed space formed by the adhesion surface between the second closed recess having a surface opening area smaller than that of the first closed recess and the micro-structure, as described by the surface opening shape of the closed recess, although weak, an attractive force acts on the micro-structure, so that the adhesion state can be stabilized.

[0032] Further, in the second invention of the present invention, a silicone rubber film is formed on a substrate, one or more convex portions are formed on the surface of the silicone rubber film on the side opposite to the substrate, and the surface of the convex portion has one or more closed recesses except for the surface opening. A stamp component for transferring a micro-structure is provided, which is characterized in that.

[0033] By doing so, by optimizing the shape, opening area (size and number), and layout of the closed recess provided on the surface of the convex portion, the temporary adhesive force of the silicone rubber film surface provided with the convex portion in contact with the microstructures can be optimized. That is, according to the second invention of the present invention, it is possible to provide a stamp component for transferring microstructures that can optimize the temporary adhesive force of the surface of the silicone rubber film stamp in a short time. Further, when the stamp component of the present invention is used, one or a plurality of microstructures can be selectively taken out from a specific region without contacting the adjacent microstructures from a supply portion in which many microstructures are densely arranged.

[0034] Also, by doing so, when the surface of the convex portion including the microstructures and the closed recess is temporarily adhered, the closed recess becomes a closed space. Since it is pressure-bonded with an optimized pushing-in amount during temporary adhesion, the closed space of the closed recess is in a reduced-pressure state at the stage of temporary adhesion. As a result, when the volume of the concave space is small, although weak, an attractive force acts on the microstructures, so that the adhesion state can be stabilized.

[0035] The convex portion may include convex-shaped protrusions of two or more stages, and the uppermost surface of the convex-shaped protrusions of two or more stages may have one or more of the closed recesses.

[0036] By doing so, by optimizing the shape, opening area (size and number), and layout of the closed recess provided on the uppermost surface of the convex-shaped protrusions of two or more stages, the temporary adhesive force of the surface of the silicone rubber film of the uppermost surface of the convex-shaped protrusions of two or more stages in contact with the microstructures can be optimized. Further, when such a stamp component is used, for even smaller microstructures, one or the microstructures in a specific region can be selectively taken out from a supply portion in which many microstructures are densely arranged without contacting the adjacent microstructures.

[0037] It is preferable that the closed recess has a bottom surface with a curvature.

[0038] By doing so, the entire bottom surface of the closed concave portion is temporarily adhered to the microstructures, and the entire surface of the closed concave portion becomes a vacuum state. As a result, since the shape restoring force of the closed concave portion exerts the adsorption force on the adhesion surface, it becomes possible to temporarily adhere the microstructures even when the adhesive force of the silicone rubber film is weak. In addition, when the adhesive force of the silicone rubber film is strong, it can be easily adjusted by reducing the adhesion area of the convex portion.

[0039] For example, the bottom surface of the closed concave portion may be spherical or aspherical.

[0040] By doing so, the microstructures and the bottom surface of the closed concave portion formed on the surface of the convex portion can be temporarily adhered with a small deformation.

[0041] For example, the shape of the surface opening of the closed concave portion may be circular or elliptical.

[0042] By doing so, the shape of the bottom surface of the closed concave portion can be made into a part of the surface of a sphere or a part of the surface of an ellipse.

[0043] When the shape of the surface opening of the closed concave portion is polygonal, it is preferable that the vertex portions of the polygon have an arc shape.

[0044] By doing so, it is possible to eliminate the inflection point of the angle at the vertex portion, so that the vacuum holding ability is improved when the microstructures are adhered to the bottom surface of the closed concave portion formed on the surface of the convex portion.

[0045] A plurality of the convex portions are formed on the surface of the silicone rubber film, and it is preferable that the plurality of convex portions are arranged in a matrix at a constant pitch in the X direction and the Y direction, respectively.

[0046] For example, in the case of an electric or electronic device or a 3D package, the transfer of microstructures to a regular layout can be performed simultaneously in a batch. Also, in the case of a micro LED display, by forming a matrix with the display pixel pitch, the micro LEDs can be transferred and arranged on the backplane substrate all at once. Thus, it is extremely useful when arranging microstructures in a matrix at a predetermined desired pitch.

[0047] The convex portion may be in a cylindrical shape, a polygonal prism shape, a frustum shape, or a multi-step shape that is a combination thereof.

[0048] As the pitch of the matrix becomes smaller, it is necessary to make the convex portion smaller so as not to interfere with adjacent microstructures. In this case, there arises a problem that the mechanical strength of the convex portion decreases. In order to strengthen the mechanical strength of the convex portion without reducing the height of the convex portion, it can be solved by gradually reducing the size (width, thickness) of the protrusion while keeping the height the same. At that time, the convex portion can be realized by combining a columnar shape or a frustum shape.

[0049] The cross-sectional shape of the convex portion in the height direction is preferably a shape convex toward the inside of the convex portion.

[0050] When the cross-sectional shape of the convex portion in the height direction, that is, the cross-sectional profile of the plane perpendicular to the substrate, is convex toward the inside of the convex portion, it is easy to avoid interference with adjacent chips. It is suitable for the case of relatively large convex portions.

[0051] Alternatively, the cross-sectional shape of the convex portion in the height direction may be a shape convex toward the outside of the convex portion.

[0052] In this case, it is effective for obtaining the mechanical strength of the convex-shaped protrusion in the case of relatively small convex-shaped protrusions.

[0053] It is preferable that a conductive film is formed between the substrate and the silicone rubber film.

[0054] In this way, when performing the transfer operation of the microstructures using the stamp component of the present invention, it is possible to suppress the electrostatic adsorption of particles such as dust generated inside the transfer machine as compared with the case where there is no conductive film.

[0055] Alternatively, it is more preferable that the silicone rubber film is a conductive film.

[0056] In this way, it is possible to omit the step of forming an extra conductive film and suppress the electrostatic adsorption of particles such as dust generated inside the transfer machine.

[0057] For example, the substrate may be a quartz substrate.

[0058] It is more preferable that the quartz substrate is a synthetic quartz substrate.

[0059] When using a synthetic quartz substrate, the flatness of the substrate is remarkably improved, so the surface flatness of the silicone rubber film is greatly improved. As a result, the transfer performance of the microstructures transfer device is remarkably improved.

[0060] Alternatively, the substrate may be a sapphire substrate.

[0061] In this way, since the mechanical strength is higher than that of a quartz (including synthetic quartz) substrate, it is possible to provide a stamp component for transferring microstructures with excellent durability.

[0062] Alternatively, the substrate may be a silicon wafer or a silicon wafer piece.

[0063] In this way, it is possible to provide a stamp component for transferring microstructures with even better flatness than a synthetic quartz substrate.

Advantages of the Invention

[0064] As described above, the stamp component for transferring microstructures, which is the first invention of the present invention, has a silicone rubber film formed on a substrate, and the surface of the silicone rubber film on the side opposite to the substrate has one or more recesses with the surface openings closed except for the surface openings. By this, not only can the adhesive force (adhesion and tack) of the silicone rubber film be adjusted by the film composition, but also the opening area (size and number) and pattern layout of the closed recesses can be adjusted to perform adjustment and optimization. That is, according to the first invention of the present invention, it is possible to provide a stamp component for transferring microstructures capable of optimizing the temporary adhesive force on the surface of the silicone rubber film stamp in a short time. Further, by having one or more recesses with the surface openings closed except for the surface openings, the suction force due to the decompression of the closed recesses can also be utilized as a control factor for the temporary adhesive force of the stamp.

[0065] The stamp component for transferring microstructures, which is the second invention of the present invention, has a silicone rubber film formed on a substrate, and one or more convex portions are formed on the surface of the silicone rubber film on the side opposite to the substrate. Since the surface of the convex portion has one or more recesses with the surface openings closed except for the surface openings, the microstructures can be temporarily adhered and transferred by the one or more convex portions. When there is one convex portion, it is useful when performing repair. On the other hand, it is also possible to transfer a large number of microstructures at once by a large number of convex portions. Further, it is also possible to transfer a large number of microstructures at once by each one convex portion. Furthermore, by laying out the convex portions in a matrix pattern at the pixel pitch, for example, in the case of a display, in the desired pattern layout of the transfer destination, it becomes possible to transfer them in a batch to the desired pattern layout.

[0066] In addition, by adjusting the adhesive force (adhesion and tack) derived from the film composition and the area (size and number) of the closed concave portions on the surface of the convex portions made of a silicone rubber film, the temporary adhesive force can be adjusted and optimized. That is, according to the second invention of the present invention, it is possible to provide a stamp component for transferring a micro-structure that can optimize the temporary adhesive force on the surface of a silicone rubber film stamp in a short time. Further, the stamp component for transferring a micro-structure of the present invention exerts force when the micro-structures are densely arranged or when several micro-structures on the supply substrate side are transferred skipping some of them.

[0067] The stamp component for transferring a micro-structure, which is an embodiment of the second invention of the present invention, includes the convex portions having convex-shaped protrusions of two or more stages, and the uppermost surface of the convex-shaped protrusions of two or more stages has one or more of the closed concave portions, so that even when the size of the micro-structure is on the order of 100 μm or further on the order of 10 μm, the mechanical strength of the convex portions required for transfer and the durability during the transfer operation can be provided.

[0068] The stamp component for transferring a micro-structure, which is another embodiment of the second invention of the present invention, has a bottom surface with a curvature for the closed concave portion, so that when the micro-structure is temporarily adhered, the bottom surface of the closed concave portion can be adhered to the adhesion surface of the micro-structure without a gap. As a result, since the adsorption force in the closed concave portion can be obtained to the maximum, the adsorption surface can generate a large temporary adhesive force in addition to the adhesive force of the silicone rubber film even if it is small.

[0069] In this way, by providing closed concave portions on the surface of the silicone rubber film or the surface of the convex portions that are temporarily adhered to the micro-structure, not only the composition and physical properties of the silicone rubber film but also the shape, opening area (size and number), layout, and adsorption force of the closed concave portions are adjusted, so that the adjustment window of the adhesive force in one silicone rubber film can be significantly improved. As a result, it can greatly contribute to the improvement of industrial productivity.

Brief Description of the Drawings

[0070]

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Embodiments for Carrying Out the Invention

[0071] As described above, there has been a demand for the development of a stamp component for transferring a micro-structure that can optimize the temporary adhesive force on the surface of a silicone rubber film stamp in a short time.

[0072] As a result of intensive studies on the above problems, the present inventors have found that by providing closed recesses on the surface of the silicone rubber film or the surface of the convex portion that temporarily adheres to the micro-structure, not only the composition and physical properties of the silicone rubber film but also the shape, opening area (size and number), layout, and adsorption force of the closed recesses can be adjusted, thereby significantly improving the adjustment window of the adhesive force in one silicone rubber film, and completed the present invention.

[0073] That is, the present invention is a stamp component for transferring a micro-structure, characterized in that a silicone rubber film is formed on a substrate, and the surface of the silicone rubber film on the side opposite to the substrate has one or more closed recesses except for surface openings.

[0074] Further, in the present invention, a silicone rubber film is formed on a substrate, and one or more convex portions are formed on the surface of the silicone rubber film on the side opposite to the substrate, and the surface of the convex portion has one or more concave portions in which portions other than the surface opening are closed. The present invention relates to a stamp component for transferring a micro-structure, characterized by the above.

[0075] Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

[0076] (First Embodiment) FIG. 1 shows a structural explanatory diagram of an example of a stamp component for transferring a micro-structure showing a first embodiment of the present invention. FIG. 1(a) is a cross-sectional view of the stamp component 100 for transferring a micro-structure, and FIG. 1(b) is a top view of the stamp component 100 for transferring a micro-structure. The cross-sectional view (a) shows the cross-sectional structure between P and Q in the top view (b). In FIG. 1, 1 is a substrate (for example, a quartz substrate), 2 is a silicone rubber film, and 3 is a closed concave portion formed on the surface 2a of the silicone rubber film 2 (the surface of the silicone rubber film on the side opposite to the substrate 1). As shown in FIG. 1, the closed concave portion 3 is closed except for the surface opening 3a. Further, as shown in FIG. 1(b), a plurality of closed concave portions 3 are arranged in a matrix on the surface 2a of the silicone rubber film.

[0077] In FIG. 1(b), the case where the shape of the surface opening of the closed concave portion 3 is square is illustrated. The shape of the surface opening of the closed concave portion 3 is not limited to a square, and may be a closed shape such as a circle, an ellipse, a ring, or a polygon such as a triangle, a rectangle (a square), or a hexagon.

[0078] Figure 2 shows an explanatory diagram of the effect of the closed concave portion of an example of the stamp component for transferring microstructures in the first embodiment of the present invention. In Figure 2, (a) is a bottom view of only the stamp component 100 for transferring microstructures of this example, and (b) and (c) are cross-sectional views. The cross-sectional views (b) and (c) show the cross-section of the P-Q portion of the bottom view (a), and show the state where the microstructure 4 is temporarily adhered to the surface 2a of the silicone rubber film. Figure 2(b) shows the case of the microstructure 4 having a surface smaller than the surface 2a of the silicone rubber film 2, and Figure 2(c) shows the case of the microstructure 4 having a surface larger than the surface 2a of the silicone rubber film 2. The stamp component 100 for transferring microstructures shown in Figure 2 is the same as the stamp component 100 for transferring microstructures shown in Figure 1.

[0079] Using Figure 2(b), the effect of the closed concave portion 3 will be described. Let the adhesion area between the silicone rubber film 2 and the microstructure 4 be S, and the total surface area of the closed concave portion 3 be A. Then, the actual temporary adhesion area is (S - A). Generally, in the case of a silicone rubber film, the temporary adhesion force mainly originates from the adhesive force and the pressure-sensitive adhesive force. That is, the temporary adhesion force is the sum of the adhesive force of the surface 2a of the silicone rubber film 2 and the tack force generated depending on the displacement amount of the surface 2a of the silicone rubber when the microstructure 4 and the silicone rubber film 2 are pressure-bonded. Since the temporary adhesion force is generated at the temporary adhesion surface between the silicone rubber film 2 and the microstructure 4, the temporary adhesion force greatly depends on the temporary adhesion area S.

[0080] In Figure 2, for the purpose of explaining the effect of the closed concave portion 3, the case of transferring one microstructure 4 is illustrated. However, when transferring a large number of microstructures at once, the temporary adhesion force can be adjusted by considering the effect of the same temporary adhesion area and adjusting the shape, opening area (size and number), and layout of the closed concave portion.

[0081] FIG. 3 shows an explanatory diagram of the structure of a closed recess in another example of the stamp component for transferring a micro-structure according to the first embodiment of the present invention. FIG. 3(a) is a cross-sectional view of the stamp component 100 for transferring a micro-structure in this example, and FIG. 3(b) is a top view. The cross-sectional view (a) shows the cross-sectional structure between P and Q in the top view (b). The difference from FIG. 2 is the layout of the closed recess 3. In FIG. 3, the matrix pattern of the closed recess 3 is laid out with a 45-degree rotation from the case of FIG. 2.

[0082] FIG. 4 shows an explanatory diagram of the structure of a closed recess in another example of the stamp component for transferring a micro-structure according to the first embodiment of the present invention. FIG. 4(a) is a cross-sectional view of the stamp component 100 for transferring a micro-structure in this example, and FIG. 4(b) is a top view. The cross-sectional view (a) shows the cross-sectional structure between P and Q in the top view (b). The differences from FIG. 2 are that a plurality of closed recesses 5 with a circular surface opening shape are formed on the silicone rubber film surface 2a, and the layout of the closed recesses 5. In FIG. 4, the closed recesses 5 are laid out on a concentric hexagonal pattern. By laying out (arranging) the closed recesses 5 in a geometric pattern like this, a regular pattern layout with some symmetries can be constructed.

[0083] In the present invention, when the micro-structure and the silicone rubber surface including the closed recess are temporarily adhered, the closed recess becomes a closed space. Since it is pressure-bonded with an optimized pushing-in amount during temporary adhesion, the closed space of the closed recess is in a reduced-pressure state at the stage of temporary adhesion. As a result, when the volume of the concave space is small, although weak, an attractive force acts on the micro-structure, so that the adhesion state can be stabilized.

[0084] Also, for example, as in the examples shown in FIGS. 1 to 4, it is preferable that the depth of the closed recess does not reach the substrate.

[0085] By doing so, since the silicone rubber film and the substrate are adhesively fixed over the entire surface, the durability is improved. As a result, the replacement frequency of the stamp component of the present invention can be reduced, and thus the productivity of the transfer of the microstructures can be improved.

[0086] (Second Embodiment) Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 5 shows a structural explanatory diagram of an example of a stamp component 100 for transferring microstructures according to the second embodiment of the present invention. FIG. 5(a) is a cross-sectional view, and FIG. 5(b) is a top view.

[0087] The difference from the first embodiment is that the size of the surface opening 6a of the closed recess 6 is relatively large. In such a case, when looking at the portion 2b of the surface 2a of the silicone rubber film 2 other than the closed recess 6 instead of the closed recess 6, as shown in FIG. 5(b), the remaining portion 2b of the surface 2a of the silicone rubber film has a lattice pattern. The structure of the stamp component 100 with a large total opening area of the closed recess 6 in this way is suitable for the case where a silicone rubber film 2 having a stronger pressure-sensitive adhesive force or adhesive force than the optimum value in the case of not having the closed recess 6 is used. In this case, by optimizing the opening area (size and number) of the closed recess 6, it can be easily optimized so as to exhibit a desired temporary adhesive force. In other words, even when a silicone rubber film 2 having a strong pressure-sensitive adhesive force or a strong adhesive force is used, if the second embodiment of the present invention is used, the temporary adhesive force of the silicone rubber film 2 can be adjusted within a considerably large range.

[0088] FIG. 6 shows a structural explanatory diagram of another example of a stamp component 100 for transferring microstructures according to the second embodiment of the present invention. FIG. 6(a) is a cross-sectional view, and FIG. 6(b) is a top view. The difference from the case of FIG. 5 is that the shape of the surface opening of the closed recess 6 in FIG. 5 is square, whereas the shape of the surface opening of the closed recess 7 in FIG. 6 is rectangular. By such a change in shape, the total area of the closed recess can also be adjusted.

[0089] FIG. 7 shows a structural explanatory diagram of another example of the stamp component 100 for transferring microstructures showing the second embodiment of the present invention. FIG. 7(a) is a cross-sectional view, and FIG. 7(b) shows a top view. The pattern layout of the closed recess 8 in FIG. 7 is obtained by rotating all the patterns of the closed recess 7 in FIG. 6 by θ, and is a kind of lattice pattern. Further, as θ is increased, a layout pattern in which the closed recesses are connected, that is, a zigzag (ZIG-ZAG) pattern and a horizontal single-character recess can be created. Therefore, these layout patterns can be called derivative layouts of the lattice pattern.

[0090] In addition, in FIGS. 5 to 7, the cross-sectional view (a) shows the cross-sectional structure between P and Q of the top view (b).

[0091] Even in the case of the recess pattern layout of the lattice pattern as in the second embodiment of the present invention, when the silicone rubber film is temporarily adhered, a closed space is formed between the closed recess and the microstructure. When the pattern size is large or the pattern depth is deep, and thus the volume of the closed space is large, the suction effect on the microstructure is small. However, as the pattern size is decreased, the volume of the closed space becomes small, so that a suction effect on the microstructure can be expected.

[0092] The portion other than the closed recess on the surface of the silicone rubber film may have a cross-sectional pattern of a honeycomb structure.

[0093] Also in this case, similar to the lattice pattern, since the surface temporarily adhered to the microstructure has a regular layout, a temporary adhesive force is uniformly generated on the temporarily adhered surface of the microstructure. As a result, a stable transfer operation can be provided.

[0094] As described above, when the microstructures and the silicone rubber surface including the concave portions are temporarily adhered, if the area of the closed concave portion is small and a closed space with a small volume is formed, when pressure-bonded with an optimized pushing-in amount during temporary adhesion, the closed space of the closed concave portion is decompressed, and thus an attractive force acts on the microstructures. The force generated in one closed concave portion is weak, but when the number thereof is extremely large, it can become a large force. Therefore, it is possible to control both the effect of providing the closed concave portions to weaken the pressure-sensitive adhesive force and the effect of strengthening the adhesive force by the attractive force of the closed concave portions. Further, the attractive force of the closed concave portions also produces an effect of stabilizing the adhesion state.

[0095] The stamp component of the second embodiment of the present invention is applicable to the transfer of microstructures of any size, but is particularly suitable for transferring microstructures that are the same size as or larger than the size of the silicone rubber film serving as the stamp. For example, it is suitable for mounting relatively large thin film chips such as semiconductor LSIs.

[0096] (Third Embodiment) FIG. 8 shows a structural explanatory diagram of a stamp component 100 for transferring microstructures showing the third embodiment of the present invention. FIG. 8(a) is a cross-sectional view, and FIG. 8(b) is a top view. The cross-sectional view (a) shows the cross-sectional structure between P and Q in the top view (b).

[0097] In FIG. 8, reference numeral 9 denotes a closed concave portion having an annular surface opening shape, which is a circumferential belt-shaped concave portion on a concentric circle. There may be one or more circumferential belt-shaped (annular shape) closed concave portions 9. The important point of this embodiment is that the concave portion 9 is closed except for the surface opening portion. When the circumferential belt width of the closed concave portion 9 is small, an attractive force in the concave portion 9 can be expected. In order to further enhance the effect, optimization of the depth of the closed concave portion 9 is also important. That is, it is important to set the depth such that the volume reduction of the concave portion leads to the generation of an attractive force.

[0098] In addition, in FIG. 8, a closed concave portion 3 having a circular surface opening shape is drawn at the center portion, but in the embodiment of the present invention, the circular concave portion at the center portion may or may not be provided.

[0099] (Embodiment 4) FIG. 9 shows a structural explanatory diagram of a stamp component 100 for transferring a micro-structure according to the fourth embodiment of the present invention.

[0100] In FIGS. 9(a) and (b), 6 and 9 are first closed recesses provided on the surface 2a of the silicone rubber film 2. 11 is a second recess, which is provided in a portion of the surface 2a of the silicone rubber film other than the first closed recess 6 or 9, and has a smaller diameter (surface opening area) than the first closed recess 6 or 9. The second recess 11 is also a recess with the outside of the surface opening closed. In the embodiment of the present invention, for example, the temporary adhesive force can be roughly adjusted by the first closed recess, and the temporary adhesive force can be finely adjusted by the second closed recess.

[0101] FIG. 9(c) is a structural explanatory diagram of a modified example of a stamp component for transferring a micro-structure according to the fourth embodiment of the present invention.

[0102] In FIG. 9(c), 11a is a recess provided on the surface 2a of the silicone rubber film, which is the same as the second recess 11 shown in FIGS. 9(a) and (b), and has the outside of the surface opening closed. Also, in FIG. 9(c), 10 indicates a groove-shaped recess provided in a portion of the surface 2a of the silicone rubber film other than the closed recess 11a. In FIG. 9(c), the direction of the groove of the recess 10 is shown in a state of being rotated by θ degrees with respect to one side of the silicone rubber film 2. The value of θ may be any angle from 0 degree to 360 degrees. Also, the internal shape of the recess 10 may be wavy or zigzag, and may have any layout shape.

[0103] (Embodiment 5) FIG. 10 shows a structural explanatory diagram of a stamp component 100 for transferring a micro-structure according to the fifth embodiment of the present invention. FIG. 10(a) is a cross-sectional view, and FIGS. 10(b) and (c) are top views. The cross-sectional view (a) shows the cross-sectional structure between P and Q in the top view (b). FIG. 10(c) is an enlarged view of a part of FIG. 10(b).

[0104] In FIG. 10, reference numeral 12 denotes a convex portion provided on the surface 2a of the silicone rubber film 2. The convex portion 12 is made of the same silicone rubber film as the silicone rubber film 2. Reference numeral 13 denotes a closed concave portion provided on the surface 12a of the convex portion. As shown in FIG. 10(c), the closed concave portion 13 is closed except for the surface opening 13a.

[0105] As shown in FIG. 10, the microstructured transfer stamp component 100 having only one convex portion 12 is useful for transferring a single microstructured body as small as in the millimeter order, 100 μm order, or even 10 μm order. In that case, the surface 12a of the convex portion 12, that is, the size of the adhesive surface may be formed to be approximately the same as the size of the microstructured body. It is more preferable to make it slightly larger than the size of the microstructured body. Thereby, the adhesive force of the peripheral portion of the microstructured body can be stabilized. Although it also depends on the position accuracy of the transfer device, in the case of a microstructured body of 10 μm to 100 μm, it is preferable to form the size of the surface 12a of the convex portion 12 to be even larger to absorb the position accuracy error of the transfer device.

[0106] When using the stamp of the present embodiment, the temporary adhesive force of the convex portion 12 that actually adheres to the microstructured body can be optimized by the size (opening area, depth), number, and layout of the closed concave portions 13 provided on the convex portion surface 12a.

[0107] In this case, by adjusting the closed concave portion 13 so that an attractive force is generated by the closed concave portion 13 formed on the convex portion surface 12a, the stability of the temporary adhesion between the adhesive surface of the microstructured body and the convex portion surface 12a can be improved.

[0108] Further, when using the microstructured transfer stamp component 100 of the present embodiment, it is possible to selectively take out one or a specific region of the microstructured bodies from a supply portion in which many microstructured bodies are densely arranged without contacting the adjacent microstructured bodies, and it is possible to arrange them at a closer position with respect to the supply side.

[0109] The stamp component 100 for transferring microstructures having one convex portion 12 according to the fifth embodiment of the present invention is useful when transferring microstructures one by one, and is particularly essential when used for repair.

[0110] (Sixth Embodiment) FIG. 11 shows a structural explanatory diagram of a stamp component 100 for transferring microstructures according to the sixth embodiment of the present invention. FIGS. 11(a), (e), and (f) are cross-sectional views, and FIGS. 11(b) to (d) show top views. Cross-sectional view (a) shows the cross-sectional structure between P-Q in top view (b). FIGS. 11(c) and (d) are enlarged views of different parts of FIG. 11(b). FIG. 11(e) shows the cross-sectional structure between R-S in FIG. 11(c). FIG. 11(f) shows the cross-sectional structure between R'-S' in FIG. 11(d).

[0111] In FIG. 11, reference numeral 14 denotes a convex portion provided on the surface 2a of the silicone rubber film 2, and shows a case where two or more convex portions are provided. The convex portion 14 is made of the same silicone rubber film as the silicone rubber film 2. Reference numeral 15 denotes a closed concave portion provided on the surface 14a of the convex portion 14. As shown in FIGS. 11(c) and (d), the closed concave portion 15 is closed except for the surface opening 15a.

[0112] FIGS. 11(c) and (e) show a case where one closed concave portion 15 is provided on the convex portion 14. On the other hand, FIGS. 11(d) and (f) show cases where two or more closed concave portions 15 are provided on the convex portion 14. In either case of FIGS. 11(c) and (d), the adhesion force can be easily adjusted by optimizing the size and number of the convex portion 14 and the size and number of the closed concave portion 15.

[0113] In the explanatory drawing of FIG. 11, since it is not easy to physically illustrate them, 49 (7×7 matrix) convex portions 14 are illustrated. However, if each one is miniaturized to form a stamp component 100 having thousands or tens of thousands of convex portions 14, inevitably, the size and interval of the convex portions 14 will be on the micron order. It can be easily inferred that the size of the closed recess 15 provided on the surface 14a of the convex portion 14 on the micron order will naturally be smaller than the scale of the convex portion 14. By using the stamp configured in this way, even when transferring many microstructures at once, the adsorption force of the closed recess 15 can be greatly utilized, and stable transfer can be realized.

[0114] (Seventh Embodiment) FIG. 12 shows a structural explanatory drawing of a stamp component 100 for transferring microstructures showing the seventh embodiment of the present invention. FIG. 12(a) shows a cross-sectional structure of a stamp component 100 for transferring microstructures of the first example, and FIG. 12(b) is a top view of the convex portion 12 shown in FIG. 12(a). FIG. 12(c) shows a cross-sectional structure of a stamp component 100 for transferring microstructures of the second example, and FIG. 12(d) is a top view of the convex portion 12 shown in FIG. 12(c).

[0115] In FIG. 12, reference numeral 16 denotes a first convex-shaped protrusion provided on the surface of the silicone rubber film 2, and reference numeral 17 denotes a second convex-shaped protrusion provided on the first convex-shaped protrusion 16. The convex portion 12 shown in FIG. 12 includes the first convex-shaped protrusion 16 and the second convex-shaped protrusion 17 at the uppermost stage. That is, the convex portion 12 shown in FIG. 12 has a protrusion structure (two-stage convex-shaped protrusion) having a two-stage convex shape. The first convex-shaped protrusion 16 and the second convex-shaped protrusion 17 are made of the same silicone rubber film as the silicone rubber film 2. Reference numeral 18 denotes a closed recess provided on the surface of the second convex-shaped protrusion 17.

[0116] In the first example shown in FIGS. 12(a) and (b), a first convex-shaped protrusion 16 is provided on the surface 2a of the silicone rubber film 2, and a second convex-shaped protrusion 17 is provided on the convex-shaped protrusion 16, forming a structure with one two-step convex portion 12. On the other hand, FIGS. 12(c) and (d) show a case where, in the two-step convex portion 12, the second convex-shaped protrusions 17 are formed in a 3×3 matrix on one first convex-shaped protrusion 16.

[0117] As shown in the fifth embodiment, when using the stamp component 100 having one convex portion 12 shown in FIG. 10, it is possible to selectively pick out one or a specific area of the microstructures from a supply portion where many microstructures are densely arranged without contacting the adjacent microstructures, and it becomes possible to arrange them at a closer position to the supply side. However, when the size of the microstructures is on the order of 100 μm or even on the order of 10 μm, the size of the adhesive surface of the convex portion of the stamp component also needs to be approximately the same as that of the microstructures. For example, the height of a convex portion with an adhesive surface of 50 μm may require a height of 50 μm or more than its double of the adhesive surface to avoid buffering with adjacent microstructures. In such a case, when the stamp is pressed in, the convex portion is likely to be damaged such as bent or broken due to repeated use. To cope with such a case, by using a two-step convex portion structure as shown in this seventh embodiment, the strength and durability can be improved.

[0118] Note that the stamp component for transferring microstructures having convex-shaped protrusions as in this embodiment exerts force when the microstructures are densely arranged or when transferring several microstructures on the supply substrate side skipping some.

[0119] As shown in FIGS. 12(c) and (d), the durability of the stamp can also be improved by adopting a structure having two or more and a relatively small number of the second protrusion-shaped protrusions 17 which are the factors causing durability problems.

[0120] (Eighth Embodiment) FIG. 13 shows an explanatory diagram of the structure of the stamp component 100 for transferring microstructures according to the eighth embodiment of the present invention. In FIG. 13, reference numeral 19 denotes a convex portion formed on the surface 2a of the silicone rubber film 2, and reference numeral 20 denotes a closed concave portion provided on the surface 19a of the convex portion 19. FIG. 13(a) is a cross-sectional view of this embodiment, and FIG. 13(b) is a top view of this embodiment. The cross-sectional view (a) shows the cross-sectional structure between P and Q in the top view (b). FIG. 13(c) is an enlarged top view of the convex portion 19, and FIG. 13(d) is an enlarged cross-sectional view of the convex portion 19.

[0121] In this case, the convex portion 19 is a quadrangular prism, the shape of the surface opening of the closed concave portion 20 is circular, and the bottom surface 20a of the closed concave portion 20 is a part of a spherical surface with a curvature r.

[0122] (Ninth Embodiment) FIG. 14 shows an explanatory diagram of the structure of the stamp component for transferring microstructures according to the ninth embodiment of the present invention.

[0123] FIG. 14(a) is a top view of the convex portion 19, FIG. 14(b) is a cross-sectional view taken along the line T-U in FIG. 14(a), and FIG. 14(c) is a cross-sectional view taken along the line V-W in FIG. 14(a). The silicone rubber film and the substrate are not shown, and only the portion of the convex portion 19 formed on the surface of the silicone rubber film is depicted. In FIG. 14, reference numeral 21 denotes a closed concave portion formed on the surface 19a of the convex portion 19.

[0124] As shown in FIG. 14(a), the basic shape of the surface opening of the closed concave portion 21 is a square, and the four vertex portions of the square are parts of arcs with a radius of curvature r0. For example, it is preferable to use 1 / 4 of an arc with a radius r0. By doing so, the tangent can be made the same between the arc and the side of the quadrilateral, and thus the deformation strain when temporarily adhering the concave bottom surface 21a to the microstructure without a gap can be reduced.

[0125] As shown in FIGS. 14(b) and (c), by changing the radius of curvature of the bottom surface 21a of the closed recess 21 in the direction (T-U) perpendicular to the sides of the quadrilateral and the diagonal direction (V-W) of the quadrilateral, and forming them at the same depth at the midpoint of the closed recess 21, the deformation of the closed recess 21 when temporarily adhering the bottom surface 21a of the recess to the microstructures without gaps can be minimized. Of course, in this case too, by optimizing the intermediate value of the two radii of curvature r1 and r2 according to the rotational angle direction between the (T-U) direction and the (V-W) direction, the bottom surface 21a of the recess 21 should be designed and formed smoothly. In this way, by using the aspherical concave bottom surface structure, the temporary adhesion force between the surface plane of the microstructures and the closed recess 21 of the convex portion surface 19a can be maximized.

[0126] (Embodiment 10) FIG. 15 shows a structural explanatory diagram of a stamp component 100 for transferring microstructures according to the tenth embodiment of the present invention. In FIG. 15, reference numeral 22 denotes a convex portion formed on the surface 2a of the silicone rubber film 2, and reference numeral 23 denotes a closed recess formed on the convex portion surface 22a.

[0127] FIG. 15(a) is a cross-sectional view of this embodiment, and FIG. 15(b) is a top view of this embodiment. The cross-sectional view (a) shows the cross-sectional structure between P-Q in the top view (b). FIG. 15(c) is an enlarged top view of the convex portion 22, and FIG. 15(d) is an enlarged cross-sectional view of the convex portion 22. In this embodiment, a large number of convex portions 22 are formed in a matrix. Further, in this embodiment, the convex portion 22 has a cylindrical shape, and a concave bottom surface shape formed of a part of a spherical surface with a radius of curvature r is formed on its surface. In this way, when the surface shape of the convex portion 22 is circular, that is, when the convex portion 22 is a shape obtained by cutting out a part of a cylinder or a conical cylinder, the deformation strain of the closed recess 23 can be reduced when the microstructures and the bottom surface 23a of the recess are temporarily adhered without gaps. In other words, after the temporary adhesion, the shape restoring force of the closed recess 23 can be made uniform, so that the temporary adhesion can be stably maintained. Even if the surface shape of the convex portion 22 is elliptical, the same effect can be obtained.

[0128] Although the case where the shape of the bottom surface 23a of the concave portion is a part of a spherical surface with a radius of curvature r has been described as an example, the bottom surface shape may be aspherical in the radial direction. For example, the bottom surface 23a of the concave portion may include a paraboloid. More precisely, by simulation, after incorporating the physical properties of the silicone rubber film to be used, the shape that is most suitable for expressing the ease of deformation during temporary adhesion and the optimal restoring force after temporary adhesion, that is, the temporary adhesion force (adhesive force + tack force + adsorption force of the silicone rubber film) may be designed.

[0129] (Embodiment 11) FIG. 16(a) shows a structural explanatory diagram of the stamp component 100 for transferring microstructures according to the 11th embodiment of the present invention. In this embodiment, the basic structure as the stamp component is the same as that of the 10th embodiment of the present invention. The difference is that, as shown in FIG. 16(a) which is a top view, the convex portions 22 are arranged in a matrix at a certain pitch (Xp, Yp) required from the placement location on the receiving substrate side.

[0130] By arranging and configuring the convex portions for gripping the microstructures in a matrix at a desired pitch in this way, it is suitable for electronic device assembly and 3D mounting in which electrical components and electronic components are arranged at a constant pitch. It is also extremely useful for the transfer assembly of micro LEDs that require arranging LEDs at a desired display pitch.

[0131] FIGS. 16(b) and (c) show an operation explanatory diagram of the stamp component 100 for transferring microstructures according to the 11th embodiment of the present invention. FIGS. 16(d) and (e) are enlarged cross-sectional views of different parts of FIG. 16(c).

[0132] In FIGS. 16(b) to (e), 24 is a supply substrate of the microstructures, and 25 and 26 are microstructures. The difference between the microstructures 25 and 26 is the size, and the case where the microstructure 25 is smaller than the area of the convex portion of the convex portion 22 and the microstructure 26 is larger than the area of the convex portion 22 is shown.

[0133] In Fig. 16(b), similar to the convex portion 22, a state is shown in which microstructures are also arranged in a desired matrix on the supply substrate 24 side. Fig. 16(c) shows a state in which the microstructures transfer stamp 100 of the present embodiment is pressed against the supply substrate 24 and the microstructures 25 and 26 are picked up from the supply substrate 24. Further, Fig. 16(d) is an enlarged view of the state in which the microstructure 25 is picked up, and shows a state in which the microstructure 25 is temporarily adhered to the bottom surface of the closed recess 23. Fig. 16(e) is an enlarged view of the state in which the microstructure 26 is picked up, and shows a state in which the microstructure 26 is temporarily adhered to the bottom surface of the closed recess 23.

[0134] As shown in Fig. 16(d), when the microstructure 25 is smaller than the convex portion 22, it is temporarily adhered so as to wrap around the periphery of the microstructure 25 in an overhang shape. On the other hand, as shown in Fig. 16(e), when the microstructure 26 is larger than the convex portion 22, the entire bottom surface of the recess adheres to the temporary adhesion surface of the microstructure 26. In either case, it is possible to temporarily adhere to the microstructures 25 and 26 like a so-called suction cup, such that the space of the closed recess 23 that existed before picking up the convex portion 22 disappears.

[0135] In the case of the first embodiment (Fig. 1) to the seventh embodiment (Fig. 12), after temporarily adhering the microstructures, the cavity of the completely closed recess did not disappear. However, by designing the recess as in the eighth embodiment (Fig. 13) to the eleventh embodiment (Fig. 16) of the present invention, no cavity is generated between the bottom surface of the recess and the adhesion surface of the microstructure.

[0136] (Twelfth Embodiment) Fig. 17 shows a structural explanatory diagram of some examples of the microstructures transfer stamp component 100 showing the twelfth embodiment of the present invention. In particular, it shows a cross-sectional view in the plane direction perpendicular to the substrate 1 of the convex portion 12, that is, in the height direction.

[0137] In Fig. 17, 27, 28, and 30 each show a part of the convex portion 12, and 29 shows a closed concave portion. 27 is the first-stage convex-shaped protrusion, 28 is the second-stage convex-shaped protrusion, and 30 is the third-stage convex-shaped protrusion.

[0138] Fig. 17(a) shows a form in which the convex portion 12 of a cylinder or prism is composed of two stages of convex-shaped protrusions 27 and 28. Fig. 17(b) shows a configuration in which the first-stage convex-shaped protrusion 27 is a cylinder or prism, and the second-stage convex-shaped protrusion 28 in the form of a frustum of a cone with a circle or polygon is formed thereon. Fig. 17(c) shows a state in which both the two-stage convex-shaped protrusions 27 and 28 are composed of frustums of a cone with a circle or polygon. Thus, by configuring the convex portion 12 with multi-stage convex-shaped protrusions, it becomes an effective means for improving the reduction in mechanical strength when the convex portion 12 is miniaturized.

[0139] Figs. 17(d) and (e) show a state in which the convex portion 12 is configured with three-stage convex-shaped protrusions 27, 28, and 30 of a frustum of a cone with a circle or polygon. Fig. 17(d) shows that the cross-sectional shape (profile) in the height direction of the convex portion 12 is convex inside the convex portion 12. Fig. 17(e) shows that the cross-sectional shape (profile) in the height direction of the convex portion 12 is convex outside the convex portion 12.

[0140] In the case of Fig. 17(d), it is useful when transferring without interfering with adjacent microstructures arranged densely when the convex portion 12 is of a relatively large size, and is also useful when the distance between the convex portion 12 and the adjacent convex portion 12 is close. On the other hand, in the case of Fig. 17(e), it is effective for preventing a reduction in the mechanical strength of the convex portion 12 when the convex portion 12 is smaller than several hundred micrometers.

[0141] Thus, by configuring the convex portion 12 in multiple stages by combining a cylinder, prism, frustum of a cone, and frustum of a pyramid, the degree of freedom in design can be greatly expanded. For more advanced design, by utilizing simulation, a smoother profile shape can be designed beyond the multi-stage combination.

[0142] In addition, in FIG. 17, although the closed concave portion 29 shows the case where the bottom surface is spherical, the effect of the cross-sectional profile of the convex portion 12 is exerted regardless of the shape of the closed concave portion 29.

[0143] In the 12th embodiment, as shown in FIG. 17, the surface of the uppermost protrusion 28 or 30 of the convex-shaped protrusions with two or more steps has a closed concave portion 29.

[0144] (13th embodiment) FIG. 18 shows a structural explanatory diagram of some examples of the stamp component 100 for transferring a micro-structure according to the 13th embodiment of the present invention.

[0145] In FIG. 18, 31 is a conductive film, which is formed between the substrate 1 and the silicone rubber film 2. FIGS. 18(a), (c), and (e) show the case where the silicone rubber film 2 does not have a convex portion, and FIGS. 18(b), (d), and (f) show the case where it has at least one convex portion 12. Although not shown, the surface 2a of the silicone rubber film 2 in FIGS. 18(a), (c), and (e), and the surface 12a of the convex portion 12 in FIGS. 18(b), (d), and (f) have closed concave portions.

[0146] FIGS. 18(a) and (b) show the case where the silicone rubber film 2 is formed in a region smaller than the substrate 1, and the conductive film 31 is formed in the same region as the silicone rubber film 2. FIGS. 18(c) and (d) show the case where the conductive rubber film 31 is formed on the entire surface of one surface of the substrate 1. Naturally, although not the entire surface of one surface of the substrate 1, the conductive film 31 may be formed in a region larger than the region of the silicone rubber film 2. FIGS. 18(e) and (f) show the case where all of the silicone rubber film 2 and the conductive film 31 are formed on the entire surface of one surface of the substrate 1.

[0147] Although the problem can be sufficiently solved by controlling the installation environment and the environment inside the apparatus of the transfer machine that performs the transfer operation using the stamp component of the present invention, it is extremely difficult to completely eliminate the risk that floating particles due to static electricity adhere to the stamp component and deteriorate the temporary adhesion with the microstructures of the stamp component. As a method for further suppressing this problem and increasing the operating time of the transfer apparatus, it is extremely effective to form the conductive film of the present embodiment between the substrate and the silicone rubber film. By configuring in this way, it is possible to greatly suppress the adsorption of particles to the adhesion surface due to static electricity.

[0148] Therefore, it is possible to simultaneously realize the two effects of adjusting the adhesive force of the silicone rubber film by the design of the closed recess and suppressing particles.

[0149] (Embodiment 14) FIG. 19 shows an explanatory diagram of the structures of some examples of the stamp component 100 for transferring microstructures showing the 14th embodiment of the present invention.

[0150] In FIG. 19, reference numeral 32 denotes a conductive silicone rubber film, and reference numerals 33 to 36 denote convex portions, showing various variations. Although not shown, the surface 32a of the silicone rubber film 32 in FIG. 19(a) and the surfaces 33a, 34a, 35a, and 36a of the convex portions 33 to 36 in FIGS. 19(b) to 19(f) have closed recesses.

[0151] In addition, in the convex portions 34 and 35 in FIGS. 19(d) and 19(e), cases where the cross-sectional shape of the convex-shaped protrusion in the final stage is a frustum shape are shown.

[0152] The greatest feature of the present embodiment is that the silicone rubber film 32 itself is a conductive film. To impart conductivity to the silicone rubber film, it can be realized by mixing a carbon-based conductive film such as carbon, carbon nanofiber, graphite, or graphene as a filler.

[0153] In FIG. 19, a state is illustrated in which a conductive silicone rubber film 32 is formed in a limited region on the substrate 1, but the conductive silicone rubber film 32 may be formed over the entire surface of the substrate 1.

[0154] By configuring in this way, it is possible to suppress particles generated during the transfer operation from adhering to the stamp component.

[0155] In the stamp component for transferring a micro-structured body described in the embodiments of the present invention above, the surface opening shape of the closed recess may be any closed shape such as a circle, an ellipse, a ring, and polygons such as a triangle, a rectangle (square, oblong), a quadrilateral, a pentagon, and a hexagon.

[0156] Regarding the surface shape of the substrate and the surface shape of the silicone rubber film, a square or rectangular shape is most convenient in terms of processing, but any shape such as a circle, an ellipse, and polygons such as a triangle, a quadrilateral, and a hexagon may be used.

[0157] The film formation of the silicone rubber film described above will be described. The film formation of the silicone rubber film of a flat film provided with a closed recess and the silicone rubber film of a structure provided with a convex portion and a closed recess on its surface can be formed by, for example, an imprint method. The curing reaction of the silicone rubber film may be heat curing or UV curing.

[0158] As a method other than the imprint method, not limited to the injection molding method, any method may be used as long as it can form the structure of the present invention.

[0159] In the stamp component for transferring a micro-structured body of the present invention, a quartz substrate can be used as the substrate. When a synthetic quartz substrate is used for the quartz substrate, the performance is dramatically improved.

[0160] In the case of a synthetic quartz substrate, in-plane uniformity (TTV: total thickness variation) of approximately 1 μm or less can be achieved, so that the in-plane height uniformity of the stamp component can be significantly improved compared to a general quartz substrate. That is, when transferring a large number of microstructures at once, all the microstructures can uniformly press the stamp component on the supply substrate side and the receiving substrate side when pressing the stamp component. More specifically, the timing at which the surface of the silicone rubber film or the convex portion formed on the surface of the silicone rubber film of the microstructure comes into contact becomes more uniform, and their pressing depths become more uniform. Therefore, when using a stamp component using a synthetic quartz substrate, a more constant temporary adhesion strength can be ensured for all of the large number of microstructures, so that stable transfer of the microstructures can be realized. Needless to say, this effect can also be obtained when transferring one microstructure with the convex portion formed on the surface of the silicone rubber film or the silicone rubber film.

[0161] Furthermore, the merit of using synthetic quartz glass is that thermal stability can be obtained. That is, the synthetic quartz glass substrate has a thermal expansion coefficient approximately 1 / 5 that of other quartz glass substrates, and thermal distortion during operation can be reduced. In particular, in the case of a stamp component having a convex-shaped protrusion, displacement and distortion (distortion) of the protrusion position due to thermal expansion and contraction can be reduced, so that its effect is exerted when performing repeated transfer operations.

[0162] Also, when using a sapphire substrate instead of a quartz substrate, since the mechanical strength is higher than that of a quartz (including synthetic quartz) substrate, a stamp component for transferring microstructures with excellent durability can be provided. Since the in-plane uniformity of the sapphire substrate surface is 15 microns or less in TTV, it is at a level that can be sufficiently used as an alternative to the quartz substrate.

[0163] Also, when using a silicon wafer or a silicon wafer piece instead of a quartz substrate, a stamp component for transferring microstructures with even better flatness than a synthetic quartz substrate can be provided.

[0164] In addition, when the size of the microstructures to be transferred is larger than approximately several hundred micrometers and flatness is acceptable, a glass substrate may be used instead of the quartz substrate.

[0165] For the silicone rubber film, for example, compositions composed of PDMS (Polydimethylsiloxane), silicone compositions with modified side chains and both ends of PDMS, and combinations thereof may be used. By adjusting the respective material compositions (molecular weight, modifying groups, modifying substances, modification amount, etc.) and in the case of mixtures, the mixing ratio, etc., physical properties such as the hardness of the material, pressure adhesive force, and repeated adhesiveness can be controlled. Not only by mixing, but also by cross-linking various modified silicone compositions with each other or three-dimensionally structuring the molecules, optimization can be achieved.

[0166] Examples of the objects to be transferred by the stamp component for transferring microstructures of the present invention include semiconductor chips and various electrical (resistors, coils, capacitors, etc.) and electronic components (diodes, transistors, thyristors, various high-performance LSI / IC chips, 3D mounting chips, SAW filter elements, MEMS chips such as acceleration sensors, and further LEDs, particularly mini-LEDs, micro-LEDs, etc.). The present invention is applicable to the mounting of these and the assembly of electrical and electronic devices.

[0167] Note that the present invention is not limited to the above-described embodiments. The above-described embodiments are examples, and any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits the same operational effects is included in the technical scope of the present invention.

Explanation of Reference Numerals

[0168] 1 and 41... Substrate (quartz substrate), 2, 42 and 43... Silicone rubber film, 2a... Surface of the silicone rubber film, 2b... Portion other than the recess, 3, 5, 6, 7, 8, 9, 11a, 13, 15, 18, 20, 21, 23 and 29... Closed recesses, 3a, 6a, 13a and 15a... Surface openings, 4, 25 and 26... Microstructures, 10... Grooved recess, 11... Second recess, 12, 14, 19, 22, 33, 34, 35, 36, 44, 45, 46, 47 and 48... Convex portions, 12a, 14a, 19a and 22a... Surfaces of the convex portions, 16... First convex-shaped protrusion, 17 and 28... Second convex-shaped protrusion, 20a and 21a... Bottom surfaces, 24... Supply substrate, 27... First-stage convex-shaped protrusion, 28... Second-stage convex-shaped protrusion, 30... Third-stage convex-shaped protrusion, 31... Conductive film, 32... Conductive silicone rubber film, 100... Stamp component for transferring microstructures, 200... Stamp.

Claims

1. A stamp part for transferring a microstructure having a rubber film on a substrate, The surface of the rubber film opposite the substrate has one or more convex portions; The convex portion has a first section and a second section along a height direction, the first section is located between the rubber membrane and the second section; the first section and the second section are frustums; a bottom surface of the frustum constituting the first section on the side of the substrate is larger than a bottom surface of the frustum on the side opposite to the substrate; A stamp part for transferring a microstructure, the bottom surface of the frustum constituting the second section facing the substrate being larger than the bottom surface on the side opposite the substrate.

2. 2. The stamp part for transferring a microstructure according to claim 1, wherein the frustum is a circular cone frustum or a polygonal pyramid frustum.

3. A stamp part for transferring a microstructure as described in claim 1, wherein the bottom surface of the frustum constituting the first section opposite the substrate side is substantially the same size as the bottom surface of the frustum constituting the second section on the substrate side.

4. 2. The stamp part for transferring a microstructure according to claim 1, wherein a bottom surface of the frustum constituting the first section on the side opposite to the substrate is larger than a bottom surface of the frustum constituting the second section on the side of the substrate.

5. 2. A stamp part for transferring a microstructure as described in claim 1, wherein a side surface of the frustum constituting the first section and a side surface of the frustum constituting the second section are connected so as to be convex toward the inside of the convex portion.

6. 2. A stamp part for transferring a microstructure as described in claim 1, wherein a side surface of the frustum constituting the first section and a side surface of the frustum constituting the second section are connected so as to be convex outwardly from the convex portion.

7. a third section on an opposite side of the second section from the substrate; the third section is a frustum; 2. The stamp part for transferring a microstructure according to claim 1, wherein a bottom surface of the frustum constituting the third section on the side facing the substrate is larger than a bottom surface on the side opposite to the substrate.

8. A stamp part for transferring a microstructure as described in claim 7, wherein the bottom surface of the frustum constituting the second section opposite the substrate side is substantially the same size as the bottom surface of the frustum constituting the third section on the substrate side.

9. 8. The stamp part for transferring a microstructure according to claim 7, wherein a bottom surface of the frustum constituting the second section opposite to the substrate side is larger than a bottom surface of the frustum constituting the third section on the substrate side.

10. A stamp part for transferring a microstructure as described in claim 7, wherein a side surface of the frustum constituting the second section and a side surface of the frustum constituting the third section are connected so as to be convex toward the inside of the convex portion.

11. A convex portion provided on a stamp for transferring a microstructure, It has a shape of two connected frustums, The base with the smaller area of ​​one frustum is connected to the base with the larger area of ​​the other frustum, A convex portion in which the base surface of the one frustum having a smaller area is substantially the same size as the base surface of the other frustum having a larger area.

12. A convex portion provided on a stamp for transferring a microstructure, It has a shape of two connected frustums, The base with the smaller area of ​​one frustum is connected to the base with the larger area of ​​the other frustum, A convex portion in which the base surface of the one frustum having a smaller area is larger than the base surface of the other frustum having a larger area.

13. A transfer method comprising the step of transferring a microstructure by using the stamp component for transferring a microstructure according to any one of claims 1 to 10.

14. A method for manufacturing an electric device, comprising the step of transferring an electric element by using the stamp part for transferring a microstructure according to any one of claims 1 to 10.

15. A method for manufacturing an electronic device, comprising the step of transferring an electronic element using the stamp component for transferring a microstructure according to any one of claims 1 to 10.

16. A method for manufacturing an LED display, comprising the step of transferring an LED using the stamp component for transferring a microstructure according to any one of claims 1 to 10.

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