Stamp component for transferring microstructure

Abstract

The present invention is a microstructured transfer stamp component characterized by having a silicone-based rubber film formed on a substrate, and the surface of the silicone-based rubber film opposite to the substrate having one or more closed concave portions other than a surface opening. Accordingly, a microstructured transfer stamp component capable of optimizing the temporary adhesion strength of the silicone-based rubber film stamp surface in a short time can be provided.

Description

Technology Field

[0001] The present invention relates to a stamp component for transferring a microstructure by a stamping method. Background Technology

[0002] Recently, with the miniaturization of semiconductor devices, microstructure transfer technology using stamps is attracting attention as a means of assembling electrical and electronic application products using semiconductor devices (Non-patent Literature 1). In particular, by using this technology to transfer a large number of miniLEDs (LEDs with a single side of 100 μm or more to several hundred μm) or microLEDs (single side of 100 μm or less, further including 50 μm or less) at once, one, multiple, or even tens of thousands, there is active development of technology to manufacture LED displays for signage, TVs, medical applications, automotive applications, pads, smartphones, smartwatches, etc., and AR / VR applications.

[0003] With the miniaturization and thinning of semiconductor chips and various electrical and electronic devices, the transfer of microstructures using stamping is being sought to replace the conventional vacuum adsorption method for device transfer in semiconductor packaging and the assembly of electronic devices. For example, a wide variety of micro-devices, such as various high-performance LSI / IC chips, micro resistors, capacitors, inductors, SAW filter elements, and MEMS chips like accelerometers, are subject to transfer.

[0004] As such, the production of microstructures using stamps is growing into an indispensable technology for manufacturing devices that will enrich and diversify our lives in the future.

[0005] It has been reported that for the adhesive layer used in the stamping method, a rubber stamp with silicone as the main component, such as PDMS (polydimethylsiloxane), can be used to receive a large number of devices from a supply substrate and transport them to a 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 a structural diagram of an example of a microstructure stamp component of the prior art.

[0007] Using FIG. 20, the structure and features of an example of a conventional stamp shown in Patent Document 2 will be briefly explained. In FIG. 20, 41 is a quartz substrate and 42 is a silicone-based rubber film. 43 is a silicone-based rubber film, and 44 to 48 are convex parts made of a silicone-based rubber film provided on the surface of the silicone-based rubber film (43).

[0008] FIG. 20(a) is a flat stamp (200) having a silicone-based rubber film (42) formed on a quartz substrate (41), and is used for transferring multiple or large quantities of microstructures at once. FIG. 20(b) to (f) shows a silicone-based rubber film (43) formed on a quartz substrate (41). Convex portions (44 to 48) are provided on the surface of the silicone-based rubber film (43) opposite to the quartz substrate (41). The stamp (200) equipped with these convex portions is used when transferring one to multiple transfer objects.

[0009] The material object is temporarily attached to the surface of the silicone rubber membrane (42) or to the surface of the uppermost part of the convex portion (44-48) by the pressure-sensitive adhesive force of the silicone rubber, moved to a predetermined position and brought into contact with the placement location, then peeled off the silicone rubber surface from the material object and placed at the predetermined position. For example, by placing a resin or the like having an adhesive force stronger than the temporary adhesive force of the silicone rubber membrane surface on the surface of the predetermined placement location, the material object can be received from the surface of the predetermined placement location and the surface of the silicone rubber membrane (42) or to the surface of the uppermost part of the convex portion (44-48) can be peeled off from the material object. At that time, the surface adhesion of the silicone-based rubber membrane, which determines material release capability, was primarily pressure-sensitive adhesion and depended on the hardness, surface adhesion, and tackiness of the silicone-based rubber membrane; therefore, the physical properties of the silicone-based rubber membrane had to be adjusted and optimized to suit the requirements arising from the characteristics of the material to be released, such as size, surface morphology, and weight, or process conditions, such as the release speed and acceleration of the material release device. Prior art literature

[0010] Specification of U.S. Patent No. 7,943,491 and Japanese Patent Publication No. 2020-129638

[0011] Matthew A. Meitl, Zheng-Tao Zhu, Vipan Kumar, Keon Jae Lee, The problem to be solved

[0012] However, with the above configuration, optimizing the temporary adhesion strength of the silicone-based rubber film stamp surface presented a problem in that it was very difficult and time-consuming to optimize the physical properties of the silicone-based rubber film to satisfy the requirements of the target material or material conditions. Furthermore, there were instances where optimization was not possible.

[0013] The present invention aims to solve the above problem by providing a microstructured transfer stamp component capable of optimizing the temporary adhesion force of the surface of a silicone-based rubber film stamp in a short period of time. means of solving the problem

[0014] To solve the above problem, the first invention of the present invention provides a microstructure transfer stamp component characterized by having a silicone-based rubber film formed on a substrate, and the surface of the silicone-based rubber film opposite to the substrate having one or more closed concave portions other than a surface opening.

[0015] In this way, by using a silicone-based rubber membrane with a pressure-sensitive adhesive force greater than the required temporary adhesive force and forming one or more closed concave portions on its surface, it is possible to adjust the surface area in contact between the microstructure, which is the material to be transferred, and the silicone-based rubber membrane to be reduced. As a result, there is no need to perform minute optimization of the pressure-sensitive adhesive force (depending on the hardness, surface adhesion, tack force, etc. of the silicone-based rubber) through synthetic phase optimization to change the physical properties of the silicone-based rubber membrane. Instead, it becomes possible to optimize the temporary adhesive force of the surface in contact with the microstructure by design modifications that optimize the shape, opening area (size and number), and layout of the closed concave portions. That is, according to the first invention of the present invention, a stamp component for transferring microstructures can be provided that can optimize the temporary adhesive force of the silicone-based rubber membrane stamp surface in a short time. Furthermore, by using the stamp component of the present invention, not only a single microstructure but also multiple or numerous microstructures can be transferred at once.

[0016] In addition, by doing so, when the surface of the silicone-based rubber membrane including the microstructure and the closed concave portion is temporarily bonded, the closed concave portion becomes a closed space. Since it is compressed with an optimized indentation amount during temporary bonding, the closed space of the closed concave portion becomes a depressurized state during the temporary bonding stage. As a result, when the volume of the concave space is small, a suction force acts on the microstructure, albeit weakly, thereby stabilizing the bonding state.

[0017] The surface opening shape of the above-mentioned closed concave portion can be selected from the group consisting of, for example, circular, elliptical, circular, and polygonal shapes.

[0018] The surface opening shape of a closed concave part can be any shape if it is a closed shape.

[0019] It is preferable that the depth of the closed concave portion does not reach the substrate.

[0020] In this way, the silicone-based rubber film and the substrate are bonded and fixed across the entire surface, thereby improving durability. As a result, the frequency of replacement of the stamp component of the present invention can be reduced, thus improving the productivity of the microstructure material.

[0021] A plurality of the closed concave portions may be arranged in a matrix shape on the surface of the above silicone-based rubber membrane.

[0022] In this way, the adhesive surface of the silicone-based rubber surface, including the microstructure and the closed concave portion, can be maintained with uniform force.

[0023] A plurality of the closed concave portions may be arranged in a geometric shape on the surface of the above silicone-based rubber membrane.

[0024] In this way, a closed concave portion with an optimal layout can be formed to match the shape of the temporary bonding surface of the microstructure to be adhered.

[0025] The portion of the surface of the silicone-based rubber membrane other than the closed concave portion may be in a grid shape.

[0026] In this way, since large concave surface openings can be formed, even when using silicone-based rubber with very strong pressure-sensitive adhesive force or, in particular, very strong adhesive force, optimization can be achieved to exhibit a desired relatively weak adhesive force by optimizing the opening area (size and number) of the concave portions.

[0027] The portion of the surface of the above silicone-based rubber membrane other than the closed concave portion may have a cross-sectional shape of a honeycomb structure.

[0028] In this case as well, similar to the grid shape, since the surface that is temporarily bonded to the microstructure has a regular layout, a uniform temporary bonding force is generated on the surface of the microstructure that is temporarily bonded. As a result, stable material transfer operation can be provided.

[0029] In the surface of the above silicone-based rubber membrane, the closed concave portion may include at least an annular concave portion.

[0030] In this way, stable temporary bonding strength can be achieved when temporarily bonding microstructures having good symmetry, such as squares or circles.

[0031] The above-mentioned closed concave portion may include a first closed concave portion and a second closed concave portion having different surface opening areas, and the surface opening area of ​​the second closed concave portion may be smaller than the surface opening area of ​​the first closed concave portion.

[0032] In this way, the adhesion area with the microstructure can be controlled at both the first closed concave portion and the second closed concave portion having a surface opening area smaller than that of the first closed concave portion. That is, the adhesion force can be roughly adjusted at the relatively large first closed concave portion, and the adhesion area and adhesion force can be finely adjusted by the second closed concave portion having a surface opening area smaller than that of the first closed concave portion. Furthermore, when the opening depth of the second closed concave portion having a surface opening area smaller than that of the first closed concave portion is minute, the adhesion state can be stabilized because, in the closed space formed by the adhesion surface of the microstructure and the second closed concave portion having a surface opening area smaller than that of the first closed concave portion, an attractive force acts on the microstructure, albeit weakly, as described regarding the surface opening shape of the closed concave portion.

[0033] In addition, the second invention of the present invention provides a microstructure transfer stamp component characterized in that a silicone-based rubber film is formed on a substrate, one or more convex portions are formed on the surface of the silicone-based rubber film opposite to the substrate, and the surface of the convex portion has one or more concave portions that are closed except for a surface opening.

[0034] In this way, by optimizing the shape, opening area (size and number), and layout of the closed concave portion provided on the surface of the convex portion, the adhesive strength of the silicone-based rubber membrane surface having the convex portion in contact with the microstructure can be optimized. That is, according to the second invention of the present invention, a stamp component for transferring microstructures can be provided that can optimize the adhesive strength of the silicone-based rubber membrane stamp surface in a short time. Furthermore, by using the stamp component of the present invention, one to a number of microstructures can be selectively extracted from a specific area without contacting neighboring microstructures from a supply portion in which many microstructures are densely arranged.

[0035] In addition, by doing so, when the surface of the convex part including the microstructure and the closed concave part is temporarily bonded, the closed concave part becomes a closed space. Since it is compressed with an optimized indentation amount during temporary bonding, the closed space of the closed concave part becomes a depressurized state during the temporary bonding stage. As a result, when the volume of the concave space is small, an attractive force acts on the microstructure, albeit weakly, thereby stabilizing the bonding state.

[0036] The above convex portion may include two or more convex protrusions, and the uppermost surface of the two or more convex protrusions may have one or more closed concave portions.

[0037] In this way, by optimizing the shape, opening area (size and number), and layout of the closed concave portion provided on the uppermost surface of the two or more convex-shaped protrusions, the adhesive strength of the silicone-based rubber film surface on the uppermost surface of the two or more convex-shaped protrusions in contact with the microstructure can be optimized. Furthermore, by using such a stamp component, for even smaller microstructures, one or a microstructure in a specific area can be selectively extracted from a supply section where many microstructures are densely arranged without contacting neighboring microstructures.

[0038] It is preferable that the above-mentioned closed concave portion has a bottom surface with curvature.

[0039] In this way, the entire bottom surface of the closed concave part is temporarily bonded to the microstructure, and the entire surface of the closed concave part becomes a vacuum. As a result, since the shape-restoring force of the closed concave part exerts the adsorption force of the adhesive surface, it becomes possible to temporarily bond the microstructure even when the adhesive force of the silicone-based rubber membrane is weak. On the other hand, if the adhesive force of the silicone-based rubber membrane is strong, it can be easily adjusted by reducing the adhesive area of ​​the convex part.

[0040] For example, the bottom surface of the closed concave portion may be spherical or aspherical.

[0041] In this way, the microstructure and the closed concave bottom surface formed on the surface of the convex part can be temporarily bonded with a small deformation.

[0042] For example, the surface opening shape of the closed concave portion may be a circle or an ellipse.

[0043] In this way, the shape of the bottom surface of the closed concave part can be made to resemble a part of the surface of a sphere or a part of the surface of an ellipse.

[0044] If the surface opening shape of the closed concave portion is polygonal, it is preferable that the vertex portion of the polygon be in the shape of an arc.

[0045] By doing so, the inflection point of the angle at the vertex can be eliminated, thereby improving the vacuum retention capability during adhesion between the surface of the microstructure and the bottom surface of the closed concave portion formed on the surface of the convex portion.

[0046] It is preferable that a plurality of convex portions are formed on the surface of the silicone-based rubber membrane, and that the plurality of convex portions are arranged in a matrix shape with a constant pitch in the X direction and Y direction, respectively.

[0047] For example, in the case of electrical and electronic devices or 3D packages, the transfer of microstructures into a regular layout can be performed simultaneously in a batch. In addition, in the case of microLED displays, microLEDs can be transferred to a backplane substrate in one go by configuring a matrix with the display pixel pitch of the display. As such, it becomes very useful when arranging microstructures in a matrix shape with a predetermined desired pitch.

[0048] The above convex part may be a cylindrical shape, a polygonal prism shape, a frustum shape, or a multi-stage shape of a combination thereof.

[0049] When the pitch of the above matrix is ​​reduced, it becomes necessary to make the convex portion smaller so as not to interfere with neighboring microstructures. In this case, a problem arises in that the mechanical strength of the convex portion is reduced. To strengthen the mechanical strength of the convex portion without reducing its height, this can be resolved by gradually reducing the size (width, thickness) of the protrusions while keeping the height the same. At that time, the convex portion can be realized by combining a columnar shape or a frustum shape.

[0050] It is preferable that the cross-sectional shape in the height direction of the above convex part is convex toward the inside of the convex part.

[0051] If the cross-sectional shape in the height direction of the convex part—that is, the cross-sectional profile of the plane perpendicular to the substrate—is convex toward the inside of the convex part, it is easy to avoid interference with adjacent chips. This is suitable for relatively large convex parts.

[0052] Alternatively, the cross-sectional shape in the height direction of the above-mentioned convex part may be a shape that is convex toward the outside of the convex part.

[0053] In this case, for relatively small convex protrusions, it is effective for obtaining the mechanical strength of the convex protrusions.

[0054] It is preferable that a conductive film be formed between the above substrate and the above silicone-based rubber film.

[0055] In this way, when performing a material transfer operation of a microstructure using the stamp component of the present invention, the electrostatic adsorption of particles such as dust generated within the material transfer device can be suppressed compared to the case where there is no conductive film.

[0056] Alternatively, it is even better if the above silicone-based rubber membrane is a conductive membrane.

[0057] By doing this, the process of forming an extra conductive film can be omitted, and the electrostatic adsorption of particles such as dust generated within the material can be suppressed.

[0058] For example, the substrate may be a quartz substrate.

[0059] It is even better if the above quartz substrate is a synthetic quartz substrate.

[0060] Using a synthetic quartz substrate dramatically improves the flatness of the substrate, thereby significantly enhancing the surface flatness of the silicone-based rubber film. As a result, the material release performance of the microstructure material release device is dramatically improved.

[0061] Alternatively, the above substrate may be a sapphire substrate.

[0062] By doing so, it is possible to provide a microstructured stamp component with excellent durability, as the mechanical strength is higher than that of a quartz (including synthetic quartz) substrate.

[0063] Alternatively, the above substrate may be a silicon wafer or a silicon wafer piece.

[0064] By doing so, it is possible to provide a microstructured stamp component with superior flatness compared to a synthetic quartz substrate. Effects of the invention

[0065] As described above, the microstructured transfer stamp component of the first invention of the present invention has a silicone-based rubber film formed on a substrate, and the surface of the silicone-based rubber film opposite to the substrate has one or more closed concave portions other than surface openings. In this way, the adhesive force (adhesion force and tack force) of the silicone-based rubber film can be adjusted and optimized not only by adjusting the film composition but also by adjusting the opening area (size and number) of the closed concave portions and the pattern layout. That is, according to the first invention of the present invention, a microstructured transfer stamp component capable of optimizing the temporary adhesive force of the silicone-based rubber film stamp surface in a short time can be provided. Furthermore, by having one or more closed concave portions other than surface openings, the suction force caused by the pressure reduction of the closed concave portions can also be utilized as a control factor for the temporary adhesive force of the stamp.

[0066] The second invention of the present invention, a microstructure transfer stamp component, has a silicone-based rubber film formed on a substrate, and one or more convex portions are formed on the surface of the silicone-based rubber film opposite to the substrate, and the surface of the convex portion has one or more concave portions that are closed except for surface openings, thereby allowing the microstructure to be temporarily attached and transferred to one or more convex portions. When there is only one convex portion, it is useful when performing repairs. Meanwhile, it is also possible to transfer multiple microstructures to multiple convex portions at once. Furthermore, multiple microstructures can be transferred to each convex portion at once. Moreover, by laying out the convex portions in a matrix shape with a desired pattern layout at the transfer site, for example, pixel pitch in the case of a display, it becomes possible to transfer them to the desired pattern layout in bulk.

[0067] Meanwhile, on the surface of a convex portion made of a silicone-based rubber film, the adhesive force (adhesion and tack force) derived from the film composition and the area (size and number) of the closed concave portions can be adjusted and optimized. That is, according to the second invention of the present invention, a stamp component for transferring microstructures can be provided that can optimize the adhesive force of the silicone-based rubber film stamp surface in a short time. Furthermore, the stamp component for transferring microstructures of the present invention exerts force when microstructures are closely arranged or when transferring microstructures on the supply substrate side by skipping a few of them.

[0068] A microstructure transfer stamp component, which is a second embodiment of the present invention, is capable of providing mechanical strength of the convex part required for transfer and durability during transfer operation even when the size of the microstructure is on the order of 100 μm or further on the order of 10 μm, by having the convex part include two or more convex protrusions and the uppermost surface of the two or more convex protrusions have one or more closed concave parts.

[0069] In another embodiment of the second invention of the present invention, the microstructure transfer stamp component has a bottom surface with curvature in the closed concave portion, so that when the microstructure is temporarily bonded, the bottom surface of the closed concave portion can be bonded to the bonding surface of the microstructure without a gap. As a result, since the adsorption force in the closed concave portion is maximized, a large temporary bonding force can be generated in addition to the adhesive force of the silicone-based rubber membrane, even if the adsorption surface is small.

[0070] In this way, by providing closed concave portions on the surface of a silicone-based rubber membrane or on the surface of a convex part that is temporarily bonded to a microstructure, the adjustment window for adhesive force in a single silicone-based rubber membrane can be significantly improved by adjusting not only the composition and physical properties of the silicone-based rubber membrane but also the shape, opening area (size and number), layout, and adsorption force of the closed concave portions. As a result, this can contribute significantly to the improvement of industrial productivity. Brief explanation of the drawing

[0071] FIG. 1 is a structural diagram illustrating an example of a microstructured stamp component representing a first embodiment of the present invention. FIG. 2 is a diagram illustrating the effect of an example of a closed concave portion of a microstructure transfer stamp part in the first embodiment of the present invention. FIG. 3 is a structural diagram of another example of a microstructure transfer stamp component in the first embodiment of the present invention. FIG. 4 is a structural diagram of another example of a microstructure transfer stamp component in the first embodiment of the present invention. FIG. 5 is a structural diagram illustrating an example of a microstructure stamp component representing a second embodiment of the present invention. FIG. 6 is a structural diagram illustrating another example of a microstructured stamp component representing a second embodiment of the present invention. FIG. 7 is a structural diagram illustrating another example of a microstructured stamp component representing a second embodiment of the present invention. FIG. 8 is a structural diagram of a microstructured stamp component representing a third embodiment of the present invention. FIG. 9 is a structural diagram of a microstructured stamp component representing a fourth embodiment of the present invention. FIG. 10 is a structural diagram of a microstructured stamp component representing a fifth embodiment of the present invention. FIG. 11 is a structural diagram of a microstructured stamp component representing the sixth embodiment of the present invention. FIG. 12 is a structural diagram of a microstructured stamp component representing the seventh embodiment of the present invention. FIG. 13 is a structural diagram of a microstructured stamp component representing the eighth embodiment of the present invention. FIG. 14 is a structural diagram of a microstructured stamp component representing the ninth embodiment of the present invention. FIG. 15 is a structural diagram of a microstructured stamp component representing the 10th embodiment of the present invention. FIG. 16 is a structural and operational diagram of a microstructured stamp component representing the 11th embodiment of the present invention. FIG. 17 is a structural diagram of a microstructured stamp component representing the 12th embodiment of the present invention. FIG. 18 is a structural diagram of a microstructured stamp component representing the 13th embodiment of the present invention. FIG. 19 is a structural diagram of a microstructured stamp component representing the 14th embodiment of the present invention. FIG. 20 is a structural diagram of an example of a microstructure stamp component of the prior art. Specific details for implementing the invention

[0072] As described above, there was a need to develop a microstructured transfer stamp component capable of optimizing the temporary adhesion strength of the silicone-based rubber membrane stamp surface in a short period of time.

[0073] The inventors, after repeatedly examining the above problem, discovered that by providing closed concave portions on the surface of a silicone-based rubber membrane or on the surface of a convex portion that is temporarily bonded to a microstructure, the adjustment window for adhesive force in a single silicone-based rubber membrane can be significantly improved by adjusting not only the composition and physical properties of the silicone-based rubber membrane but also the shape, opening area (size and number), layout, and adsorption force of the closed concave portions. Based on this discovery, the present invention was completed.

[0074] That is, the present invention is a microstructured transfer stamp component characterized by having a silicone-based rubber film formed on a substrate, and the surface of the silicone-based rubber film opposite to the substrate having one or more closed concave portions other than a surface opening.

[0075] In addition, the present invention is a microstructure transfer stamp component characterized by having a silicone-based rubber film formed on a substrate, one or more convex portions formed on the surface of the silicone-based rubber film opposite to the substrate, and the surface of the convex portion having one or more concave portions closed except for a surface opening.

[0076] The present invention will be described in detail below, but the invention is not limited to these.

[0077] (First embodiment)

[0078] FIG. 1 is a structural diagram illustrating an example of a microstructure transfer stamp component representing a first embodiment of the present invention. FIG. 1(a) is a cross-sectional view of a microstructure transfer stamp component (100), and FIG. 1(b) is a top view of a microstructure transfer stamp component (100). The cross-sectional view (a) shows the cross-sectional structure of the PQ in the top view (b). In FIG. 1, 1 is a substrate (e.g., a quartz substrate), 2 is a silicone-based rubber film, and 3 represents a closed concave portion formed on the surface of the silicone-based rubber film (2) (the silicone-based rubber film surface opposite to the substrate (1)) (2a). As shown in FIG. 1, the closed concave portion (3) is closed except for the surface opening (3a). In addition, as shown in FIG. 1(b), a plurality of closed concave portions (3) are arranged in a matrix shape on the surface (2a) of a silicone-based rubber film.

[0079] In FIG. 1(b), the surface opening shape of the closed concave portion (3) is exemplified as being square. The surface opening shape of the closed concave portion (3) is not limited to a square, but may have a closed shape such as a circle, ellipse, ring, or polygon such as a triangle, rectangle, or hexagon.

[0080] FIG. 2 is a diagram illustrating the effect of a closed concave portion of an example of a microstructure transfer stamp part in the first embodiment of the present invention. In FIG. 2, (a) is a bottom view of only the microstructure transfer stamp part (100) of this example, and (b) and (c) are cross-sectional views. Cross-sectional views (b) and (c) show the cross-section of the PQ portion of the bottom view (a) and show the state in which the microstructure (4) is temporarily attached to the surface (2a) of the silicone-based rubber film. FIG. 2(b) illustrates the case where the microstructure (4) has a surface smaller than the surface (2a) of the silicone-based rubber film (2), and FIG. 2(c) illustrates the case where the microstructure (4) has a surface larger than the surface (2a) of the silicone-based rubber film (2). The microstructure transfer stamp part (100) shown in FIG. 2 is identical to the microstructure transfer stamp part (100) shown in FIG. 1.

[0081] Using FIG. 2(b), the effect of the closed concave portion (3) is explained. If the adhesive area between the silicone-based rubber membrane (2) and the microstructure (4) is S and the sum of the surface areas of the closed concave portion (3) is A, then the actual adhesive area is (SA). Generally, in the case of a silicone-based rubber membrane, the adhesive force originates mainly from the adhesive force and the pressure-sensitive adhesive force. That is, the adhesive force is the sum of the adhesive force of the surface (2a) of the silicone-based rubber membrane (2) and the tack force generated by the amount of displacement of the silicone-based rubber surface (2a) when the microstructure (4) and the silicone-based rubber membrane (2) are compressed. Since the adhesive force is generated at the adhesive surface between the silicone-based rubber membrane (2) and the microstructure (4), the adhesive force depends greatly on the adhesive area (S).

[0082] Meanwhile, in FIG. 2, to explain the effect of the closed concave portion (3), a case in which one microstructure (4) is transferred is illustrated. However, in the case in which multiple microstructures are transferred at once, the adhesive strength can be adjusted by adjusting the shape, opening area (size and number), and layout of the closed concave portion, taking into account the effect of the same adhesive area.

[0083] FIG. 3 is a diagram illustrating the structure of a closed concave portion in another example of a microstructure transfer stamp part in the first embodiment of the present invention. FIG. 3(a) is a cross-sectional view of the microstructure transfer stamp part (100) in this example, and FIG. 3(b) is a top view. The cross-sectional view (a) shows the cross-sectional structure of the PQ in the top view (b). The difference from FIG. 2 is the layout of the closed concave portion (3), and in FIG. 3, the matrix shape pattern of the closed concave portion (3) is laid out rotated 45 degrees from the case of FIG. 2.

[0084] FIG. 4 is a diagram illustrating the structure of a closed concave portion in another example of a microstructure transfer stamp part in the first embodiment of the present invention. FIG. 4(a) is a cross-sectional view of the microstructure transfer stamp part (100) in this example, and FIG. 4(b) is a top view. The cross-sectional view (a) shows the cross-sectional structure of the PQ in the top view (b). The difference from FIG. 2 is that a plurality of closed concave portions (5) with a circular surface opening shape are formed on the silicone-based rubber film surface (2a), and the layout of the closed concave portions (5) is such that in FIG. 4, the closed concave portions (5) are laid out on a concentric hexagonal shape. By laying out the closed concave portions (5) in such a geometric shape, a regular pattern layout with several symmetries can be constructed.

[0085] In the present invention, when a silicone-based rubber surface including a microstructure and the closed concave portion is temporarily bonded, the closed concave portion becomes a closed space. Since it is compressed with an optimized indentation amount during temporary bonding, the closed space of the closed concave portion becomes a depressurized state during the temporary bonding stage. As a result, when the volume of the concave space is small, an attractive force acts on the microstructure, albeit weakly, thereby stabilizing the bonding state.

[0086] In addition, as shown in the examples in FIGS. 1 to 4, it is preferable that the depth of the closed concave portion does not reach the substrate.

[0087] In this way, the silicone-based rubber film and the substrate are bonded and fixed across the entire surface, thereby improving durability. As a result, the frequency of replacement of the stamp component of the present invention can be reduced, thus improving the productivity of the microstructure material.

[0088] (Second embodiment)

[0089] Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.

[0090] FIG. 5 is a structural diagram illustrating an example of a microstructure transfer stamp part (100) representing a second embodiment of the present invention. FIG. 5(a) is a cross-sectional view, and FIG. 5(b) is a top view.

[0091] The difference from the first embodiment is that the size of the surface opening (6a) of the closed concave portion (6) is relatively large. In this case, if we look at the portion (2b) other than the closed concave portion (6) of the surface (2a) of the silicone-based rubber membrane (2) rather than the closed concave portion (6), as shown in FIG. 5(b), the remaining portion (2b) of the silicone-based rubber membrane surface (2a) is shaped like a grid. The structure of the stamp part (100) having a large total opening area of ​​the closed concave portion (6) is suitable for cases where a silicone-based rubber membrane (2) is used that has a stronger pressure-sensitive adhesive force or adhesive force than the optimal value in the case without the closed concave portion (6). In this case, by optimizing the opening area (size and number) of the closed concave portion (6), it is easy to optimize to exhibit the necessary adhesive force. In other words, even when using a silicone-based rubber membrane (2) having strong pressure-sensitive adhesive force or strong adhesive force, the adhesive force of the silicone-based rubber membrane (2) can be adjusted over a considerably large range by using the second embodiment of the present invention.

[0092] FIG. 6 is a structural diagram illustrating another example of a microstructure transfer stamp part (100) representing a 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 FIG. 5 is that while the surface opening shape of the closed concave part (6) in FIG. 5 is square, the surface opening shape of the closed concave part (7) in FIG. 6 is rectangular. By changing the shape, the total area of ​​the closed concave part may be adjusted.

[0093] FIG. 7 is a structural diagram illustrating another example of a microstructure transfer stamp part (100) representing a second embodiment of the present invention. FIG. 7(a) is a cross-sectional view, and FIG. 7(b) is a top view. The pattern layout of the closed concave portion (8) in FIG. 7 is obtained by rotating the entire pattern of the closed concave portion (7) in FIG. 6 by θ, and is a type of grid shape. Furthermore, if θ is increased, a layout pattern shape in which the closed concave portions are connected, that is, a zig-zag shape and a horizontal straight concave portion can be created. Therefore, these layout pattern shapes can be described as a grid-shaped derivative layout.

[0094] Meanwhile, in FIGS. 5 to 7, cross-sectional view (a) shows the cross-sectional structure of PQ in top view (b).

[0095] Even in the case of a grid-shaped concave pattern layout as in the second embodiment of the present invention, when a silicone-based rubber membrane is temporarily bonded, the space between the closed concave portion and the microstructure becomes a closed space. When the pattern size is large or the pattern depth is deep, the suction effect on the microstructure is small when the volume of the closed space is large; however, when the pattern size is reduced, the volume of the closed space decreases, so a suction effect on the microstructure can be expected.

[0096] The portions of the silicone-based rubber membrane surface other than the closed concave areas may have a cross-sectional shape of a honeycomb structure.

[0097] In this case as well, similar to the grid shape, since the surface that is temporarily bonded to the microstructure has a regular layout, a uniform temporary bonding force is generated on the surface of the microstructure that is temporarily bonded. As a result, stable material transfer operation can be provided.

[0098] As described above, when a silicone-based rubber surface including a microstructure and the concave portion is temporarily bonded, if the area of ​​the closed concave portion is small and a closed space with a small volume is formed, then when compressed with an optimized indentation amount during temporary bonding, the closed space of the closed concave portion becomes a depressurized state, thereby causing an attractive force to act on the microstructure. The force generated from a single closed concave portion is weak, but if there are many of them, it can become a large force. Therefore, it becomes possible to control both the effect of weakening the depressurized adhesive force by providing the closed concave portion and the effect of strengthening the adhesive force by the attractive force of the closed concave portion. In addition, the attractive force of the closed concave portion also creates an effect of stabilizing the adhesive state.

[0099] The stamp component of the second embodiment of the present invention is applicable to microstructure materials of all sizes, and is particularly suitable for transporting microstructures that are the same size as or larger than the silicone-based rubber film that serves as the stamp. For example, it is suitable for mounting relatively large thin-film chips, such as semiconductor LSIs.

[0100] (Third embodiment)

[0101] FIG. 8 is a structural diagram of a microstructure transfer stamp part (100) representing a 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 of the PQ in the top view (b).

[0102] In FIG. 8, 9 is a closed concave portion with a surface opening shape that is an annular shape and a concentric band-shaped concave portion. There may be one or more closed concave portions (9) with an annular shape. An important point of this embodiment is that the concave portion (9) is closed except for the surface opening. When the width of the band of the closed concave portion (9) is small, suction force can be expected in the concave portion (9). To further enhance this effect, it is also important to optimize the depth of the closed concave portion (9). That is, it is important to set the depth such that the reduction in the volume of the concave portion leads to the generation of suction force.

[0103] Meanwhile, in FIG. 8, a circular closed concave portion (3) with a surface opening shape is drawn in the center, but in an embodiment of the present invention, the circular concave portion in the center may or may not be present.

[0104] (Fourth embodiment)

[0105] FIG. 9 is a structural diagram of a microstructure transfer stamp part (100) representing a fourth embodiment of the present invention.

[0106] In FIG. 9(a) and (b), 6 and 9 are first closed concave portions provided on the surface (2a) of the silicone-based rubber membrane (2). 11 is a second concave portion and represents a concave portion having a smaller diameter (surface opening area) than the first closed concave portion (6 or 9) provided on a portion of the silicone-based rubber membrane surface (2a) other than the first closed concave portion (6 or 9). The second concave portion (11) is also a closed concave portion other than the surface opening. In an embodiment of the present invention, for example, it is possible to roughly adjust the adhesive force at the first closed concave portion and finely adjust the adhesive force by the second closed concave portion.

[0107] FIG. 9(c) is a structural diagram illustrating a modified example of a microstructured stamp part representing a fourth embodiment of the present invention.

[0108] In FIG. 9(c), 11a is a closed concave portion, except for the surface opening, provided on the surface (2a) of the silicone rubber-based rubber membrane, identical to the second concave portion (11) shown in FIG. 9(a) and (b). Also in FIG. 9(c), 10 represents a groove-shaped concave portion provided on the surface (2a) of the silicone rubber-based rubber membrane, excluding the closed concave portion (11a). FIG. 9(c) shows a state in which the direction of the groove of the concave portion (10) is rotated by θ degrees relative to one side of the silicone rubber-based rubber membrane (2). The value of θ can be any angle from 0 degrees to 360 degrees. Additionally, the internal shape of the concave portion (10) may be wavy, zigzag, or any layout shape.

[0109] (Fifth embodiment)

[0110] FIG. 10 is a structural diagram illustrating a microstructure transfer stamp part (100) representing a fifth embodiment of the present invention. FIG. 10(a) is a cross-sectional view, and FIG. 10(b) and (c) are top views. The cross-sectional view (a) shows the cross-sectional structure between PQs of the top view (b). FIG. 10(c) is an enlarged view of a part of FIG. 10(b).

[0111] In FIG. 10, 12 is a convex portion provided on the surface (2a) of the silicone-based rubber membrane (2). The convex portion (12) is made of the same silicone-based rubber membrane as the silicone-based rubber membrane (2). 13 is 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).

[0112] As shown in FIG. 10, a microstructure transfer stamp part (100) having only one convex portion (12) is useful for transferring a single microstructure that is truly small, such as a millimeter order, a 100 μm order, or even a 10 μm order. In that case, the size of the surface (12a) of the convex portion (12), that is, the adhesive surface, should be formed to be approximately the same size as the microstructure. It is more desirable to make it slightly larger than the size of the microstructure. This allows the adhesive force of the periphery of the microstructure to be stabilized. Although it depends on the positional accuracy of the transfer device, in the case of a microstructure of 10 μm to 100 μm, it is desirable to form the size of the surface (12a) of the convex portion (12) to be larger enough to absorb the positional accuracy error of the transfer device.

[0113] By using the stamp of the present embodiment, the adhesive strength of the convex part (12) that actually adheres to the microstructure can be optimized by the size (opening area, depth), number, and layout of the closed concave part (13) provided on the surface (12a) of the convex part.

[0114] Meanwhile, in this case, by adjusting the closed concave portion (13) so that a suction force is generated by the closed concave portion (13) formed on the convex surface (12a), the stability of the temporary adhesion between the adhesive surface of the microstructure and the convex surface (12a) can be improved.

[0115] In addition, by using the microstructure transfer stamp component (100) of the present embodiment, one or more microstructures in a specific area can be selectively extracted from a supply section in which many microstructures are densely arranged without contacting neighboring microstructures, and it becomes possible to arrange them in a position closer to the supply side.

[0116] A microstructure transfer stamp part (100) having one convex part (12) of the fifth embodiment of the present invention is useful when transferring microstructures one by one, and is particularly essential when used for repair.

[0117] (6th embodiment)

[0118] FIG. 11 is a structural diagram illustrating a microstructure transfer stamp part (100) representing a sixth embodiment of the present invention. FIG. 11(a), (e), and (f) are cross-sectional views, and FIG. 11(b) to (d) are top views. Cross-sectional view (a) shows the cross-sectional structure between PQ in the top view (b). FIG. 11(c) and (d) are enlarged views of different parts of FIG. 11(b). FIG. 11(e) shows the cross-sectional structure between RS in FIG. 11(c). FIG. 11(f) shows the cross-sectional structure between R' and S' in FIG. 11(d).

[0119] In FIG. 11, 14 is a convex portion provided on the surface (2a) of the silicone-based rubber membrane (2), and shows a case where two or more are provided. Also, the convex portion (14) is made of the same silicone-based rubber membrane as the silicone-based rubber membrane (2). 15 is a closed concave portion provided on the surface (14a) of the convex portion (14). As shown in FIG. 11(c) and (d), the closed concave portion (15) is closed except for the surface opening (15a).

[0120] FIGS. 11(c) and (e) illustrate a case where one closed concave portion (15) is provided on the convex portion (14). In contrast, FIGS. 11(d) and (f) illustrate a case where two or more closed concave portions (15) are provided on the convex portion (14). In either FIGS. 11(c) or (d), the adhesive strength can be easily adjusted by optimizing the size and number of the convex portion (14) and the size and number of the closed concave portions (15).

[0121] In the explanatory diagram of FIG. 11, since it is not easy to illustrate physically, 49 (7×7 matrix) convex parts (14) are illustrated. However, by miniaturizing each one to form a stamp part (100) equipped with thousands or tens of thousands of convex parts (14), the size and spacing of the convex parts (14) inevitably become micron-order in size. It is also easily conceived that the size of the closed concave part (15) provided on the surface (14a) of the micron-order convex part (14) will naturally become smaller than the scale of the convex part (14). When using a stamp configured in this way, even when transferring many microstructures at once, the adsorption force of the closed concave part (15) can be utilized to a great extent, and stable transfer is realized.

[0122] (Seventh embodiment)

[0123] FIG. 12 is a structural diagram illustrating a microstructure transfer stamp part (100) representing a seventh embodiment of the present invention. FIG. 12(a) shows a cross-sectional structure of a microstructure transfer stamp part (100) of a 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 microstructure transfer stamp part (100) of a second example, and FIG. 12(d) is a top view of the convex portion (12) shown in FIG. 12(c).

[0124] In FIG. 12, 16 is a first convex-shaped protrusion provided on the surface of the silicone-based rubber membrane (2), and 17 is 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 top. That is, the convex portion (12) shown in FIG. 12 is 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-based rubber membrane as the silicone-based rubber membrane (2). 18 is a closed concave portion provided on the surface of the second convex-shaped protrusion (17).

[0125] In the first example shown in FIGS. 12(a) and (b), a first convex-shaped protrusion (16) is provided on the surface (2a) of a silicone-based rubber membrane (2), and a second convex-shaped protrusion (17) is provided on the convex-shaped protrusion (16), so that a structure is formed in which a two-stage convex portion (12) is formed. Meanwhile, FIGS. 12(c) and (d) show a case in which, in the two-stage convex portion (12), a second convex-shaped protrusion (17) is formed in a 3×3 matrix shape on one of the first convex-shaped protrusions (16).

[0126] As shown in the fifth embodiment, by using a stamp part (100) having one convex portion (12) as shown in FIG. 10, one or more microstructures in a specific area can be selectively extracted from a supply portion where many microstructures are densely arranged without contacting neighboring microstructures, and it becomes possible to arrange them in a position closer to the supply side. However, when the size of the microstructures is on the order of 100 μm, or further on the order of 10 μm, the size of the adhesive surface of the convex portion of the stamp part must also be approximately the same as that of the microstructures. For example, in order to avoid cushioning with adjacent microstructures, the height of the convex portion having an adhesive surface of 50 μm may require a height of 50 μm or more than twice that of the adhesive surface. In such cases, damage such as bending or breaking of the convex portion due to repeated use occurs when pressing the stamp. To address such cases, strength and durability can be improved by using a two-stage convex structure as shown in the seventh embodiment.

[0127] Meanwhile, a microstructure transfer stamp component having a convex protrusion as in the present embodiment exerts force when microstructures are closely arranged or when transferring microstructures on the supply substrate side by skipping a few.

[0128] As shown in FIG. 12(c) and (d), the durability of the stamp can be improved by having a structure that includes two or more second convex protrusions (17) which are a factor in the occurrence of durability issues, and also a relatively small number of them.

[0129] (Eighth embodiment)

[0130] FIG. 13 is a structural diagram illustrating a microstructure transfer stamp part (100) representing the eighth embodiment of the present invention. In FIG. 13, 19 is a convex portion formed on the surface (2a) of a silicone-based rubber membrane (2), and 20 is a closed concave portion provided on the surface (19a) of the convex portion (19). FIG. 13(a) is a cross-sectional view of the present embodiment, and FIG. 13(b) is a top view of the present embodiment. The cross-sectional view (a) shows the cross-sectional structure of the PQ 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).

[0131] In this example, the convex portion (19) is a square prism, the surface opening shape of the closed concave portion (20) is circular, and the bottom surface (20a) of the closed concave portion (20) is part of a spherical surface of curvature (r).

[0132] (Ninth embodiment)

[0133] FIG. 14 is a structural diagram of a microstructured stamp component representing the ninth embodiment of the present invention.

[0134] FIG. 14(a) shows a top view of a portion of the convex part (19), FIG. 14(b) shows a cross-sectional view of the TU surface of FIG. 14(a), and FIG. 14(c) shows a cross-sectional view of the VW surface of FIG. 14(a). The silicone-based rubber membrane and the substrate are not shown, and only the portion of the convex part (19) formed on the surface of the silicone-based rubber membrane is drawn. In FIG. 14, 21 is a closed concave portion formed on the surface (19a) of the convex part (19).

[0135] 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 vertices of the square are part of an arc with a radius of curvature (r0). For example, it is good to use 1 / 4 of an arc with a radius (r0). Then, since the tangent between the arc and the side of the square can be made equal, the deformation distortion when the bottom surface (21a) of the concave portion is temporarily attached to the microstructure without gaps can be reduced.

[0136] As shown in FIG. 14(b) and (c), by changing the radius of curvature of the bottom surface (21a) of the closed concave portion (21) in the direction perpendicular to the side of the square (TU) and the diagonal direction (VW) of the square, and by forming it at the same depth at the midpoint of the closed concave portion (21), the deformation of the closed concave portion (21) can be minimized when the bottom surface (21a) of the concave portion is temporarily bonded to the microstructure without gaps. In this case as well, of course, between the (TU) direction and the (VW) direction, it is preferable to design and form the bottom surface (21a) of the concave portion (21) smoothly by optimizing the intermediate value of the two radii of curvature (r1 and r2) according to the rotation angle direction. In this way, by using the non-spherical concave bottom surface structure, the adhesive force between the surface plane of the microstructure and the closed concave portion (21) of the convex portion surface (19a) can be maximized.

[0137] (10th embodiment)

[0138] FIG. 15 is a structural diagram of a microstructure transfer stamp part (100) representing the 10th embodiment of the present invention. In FIG. 15, 22 is a convex portion formed on the surface (2a) of a silicone-based rubber membrane (2), and 23 is a closed concave portion formed on the surface (22a) of the convex portion.

[0139] FIG. 15(a) is a cross-sectional view of the present embodiment, and FIG. 15(b) is a top view of the present embodiment. Cross-sectional view (a) shows the cross-sectional structure of PQ 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 the present embodiment, a plurality of convex portions (22) are formed in a matrix shape. In addition, in the present embodiment, the convex portion (22) is cylindrical in shape, and a concave bottom surface shape formed as part of a spherical surface with a radius of curvature (r) is formed on its surface. In this way, if the surface shape of the convex part (22) is circular, that is, if the convex part (22) is shaped like a cylinder or a part of a conical column cut off, the deformation distortion of the closed concave part (23) can be reduced when the microstructure and the bottom surface (23a) of the concave part are temporarily bonded without a gap. In other words, since the shape restoring force of the closed concave part (23) can be uniformized after temporary bonding, the temporary bond can be maintained stably. The same effect is obtained even if the surface shape of the convex part (22) is elliptical.

[0140] Meanwhile, although the example was given where the shape of the bottom surface (23a) of the concave portion is part of a spherical surface with a radius of curvature (r), the bottom surface shape may be non-spherical in the radial direction. For example, the bottom surface (23a) of the concave portion may include a parabolic surface. More strictly, after incorporating the physical properties of the silicone-based rubber membrane used through simulation, the best shape that exhibits ease of deformation during temporary bonding and optimal restoring force after temporary bonding, that is, temporary bonding force (adhesion force of the silicone-based rubber membrane + tack force + adsorption force), should be designed.

[0141] (11th embodiment)

[0142] FIG. 16(a) is a structural diagram of a microstructure transfer stamp component (100) representing the 11th embodiment of the present invention. In this embodiment, the basic structure as a 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 portion (22) is arranged in a matrix shape with a constant pitch (Xp, Yp) required from the placement location on the receiving substrate side.

[0143] In this way, by arranging and configuring convex parts that grasp microstructures in a matrix shape at a desired pitch, it is suitable for electronic device assembly or 3D packaging where electrical or electronic components are arranged at a constant pitch. In addition, it is very useful for the reassembly of microLEDs that require placing LEDs at a desired display pitch.

[0144] FIGS. 16(b) and (c) illustrate the operation of a microstructure transfer stamp component (100) representing the 11th embodiment of the present invention. FIGS. 16(d) and (e) are enlarged cross-sectional views of different parts of FIG. 16(c).

[0145] In FIGS. 16(b) to (e), 24 is a supply substrate for a microstructure, and 25 and 26 are microstructures. The difference between the microstructure (25) and the microstructure (26) is size, and 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).

[0146] In FIG. 16(b), a state is shown in which a microstructure is arranged in a desired matrix shape on the supply substrate (24) side, identical to the convex portion (22). FIG. 16(c) shows a state in which the microstructure transfer stamp (100) of the present embodiment is extruded onto the supply substrate (24) and the microstructures (25 and 26) are grasped from the supply substrate (24). Furthermore, FIG. 16(d) is an enlarged view of the state in which the microstructure (25) is grasped, showing a state in which the microstructure (25) is temporarily attached to the bottom surface of the closed concave portion (23). FIG. 16(e) is an enlarged view of the state in which the microstructure (26) is grasped, showing a state in which the microstructure (26) is temporarily attached to the bottom surface of the closed concave portion (23).

[0147] As shown in FIG. 16(d), when the microstructure (25) is smaller than the convex portion (22), it is temporarily bonded to wrap around 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 concave portion is bonded to the temporary bonding surface of the microstructure (26). In either case, the microstructure (25 and 26) can be temporarily bonded like a so-called suction cup, so that the space of the closed concave portion (23) that existed before the convex portion (22) is grasped disappears.

[0148] In the case of the first embodiment (Fig. 1) to the seventh embodiment (Fig. 12), the void in the completely closed concave portion did not disappear after the microstructure was temporarily bonded, but by designing the concave portion as in the eighth embodiment (Fig. 13) to the eleventh embodiment (Fig. 16) of the present invention, a void does not occur between the bottom surface of the concave portion and the adhesive surface of the microstructure.

[0149] (12th embodiment)

[0150] FIG. 17 shows a structural diagram of several examples of a microstructured stamp component (100) representing the 12th embodiment of the present invention. In particular, it shows a cross-sectional view in the planar direction, i.e., the height direction, perpendicular to the substrate (1) of the convex part (12).

[0151] In FIG. 17, 27, 28, and 30 represent parts of the convex portion (12), and 29 represents a closed concave portion. 27 is the first stage convex projection, 28 is the second stage convex projection, and 30 is the third stage convex projection.

[0152] FIG. 17(a) shows a form in which a convex portion (12) of a cylinder or polygonal prism is configured in two stages of convex projections (27 and 28). FIG. 17(b) shows a configuration in which the first stage of convex projections (27) is a cylinder or polygonal prism, and the second stage of convex projections (28) of a circle or polygonal frustum is formed on top of it. FIG. 17(c) shows a state in which both stages of convex projections (27 and 28) are configured in a circle or polygonal frustum. Thus, by configuring the convex portion (12) with multiple stages of convex projections, it becomes an effective means to improve the reduction in mechanical strength when the convex portion (12) is reduced.

[0153] FIGS. 17(d) and (e) show a state in which a convex part (12) is formed with three convex projections (27, 28 and 30) of a circular or polygonal frustum. FIG. 17(d) shows a cross-sectional shape (profile) in the height direction of the convex part (12) that is convex toward the inside of the convex part (12). FIG. 17(e) shows a cross-sectional shape (profile) in the height direction of the convex part (12) that is convex toward the outside of the convex part (12).

[0154] In the case of FIG. 17(d), it is useful when the convex portion (12) is relatively large in size and is placed without interfering with adjacent microstructures that are densely arranged, and it is also useful when the distance between the convex portion (12) and adjacent convex portions (12) is short. On the other hand, in the case of FIG. 17(e), it is effective in preventing a decrease in mechanical strength of the convex portion (12) when the convex portion (12) is smaller than several hundred μm.

[0155] In this way, by configuring the convex part (12) in multiple stages by combining a cylinder, a polygonal prism, a truncated cone, and a truncated polygonal cone, the degree of freedom of design can be greatly expanded. Furthermore, to design more highly, by utilizing simulation, a smoother profile shape can be designed beyond the combination of multiple stages.

[0156] Meanwhile, in FIG. 17, the closed concave portion (29) is shown as having a spherical bottom surface, but the effect of the cross-sectional profile of the convex portion (12) is exhibited regardless of the shape of the closed concave portion (29).

[0157] In the 12th embodiment, as shown in FIG. 17, the surface of the uppermost projection (28 or 30) of the two or more convex projections has a closed concave portion (29).

[0158] (13th embodiment)

[0159] FIG. 18 shows a structural diagram of several examples of a microstructure transfer stamp part (100) representing the 13th embodiment of the present invention.

[0160] In FIG. 18, 31 is a conductive film and is formed between a substrate (1) and a silicone-based rubber film (2). FIG. 18(a), (c) and (e) show a case where the silicone-based rubber film (2) does not have a convex portion, and FIG. 18(b), (d) and (f) show a case where at least one convex portion (12) is present. Meanwhile, although not shown, the surface (2a) of the silicone-based rubber film (2) in FIG. 18(a), (c) and (e), and the surface (12a) of the convex portion (12) in FIG. 18(b), (d) and (f) have a closed concave portion.

[0161] FIGS. 18(a) and (b) illustrate a case where a silicone-based rubber film (2) is formed in an area smaller than the substrate (1), and a conductive film (31) is formed in the same area as the silicone-based rubber film (2). FIGS. 18(c) and (d) illustrate a case where the conductive rubber film (31) is formed on the entire surface of one side of the substrate (1). Of course, the conductive film (31) may be formed in an area larger than the area of ​​the silicone-based rubber film (2), although not on the entire surface of one side of the substrate (1). FIGS. 18(e) and (f) illustrate a case where the entire silicone-based rubber film (2) and the conductive film (31) are formed on the entire surface of one side of the substrate (1).

[0162] Although this problem can be sufficiently resolved by controlling the installation environment and the internal environment of the material release machine performing the material release operation using the stamp component of the present invention, it is very difficult to completely eliminate the risk that airborne particles caused by static electricity will adhere to the stamp component and degrade the temporary adhesion with the microstructure of the stamp component. As a method to further suppress this problem and extend the operating time of the material release device, forming the conductive film of this embodiment between the substrate and the silicone-based rubber film is very effective. By configuring it in this way, the adsorption of particles onto the adhesive surface by static electricity can be significantly suppressed.

[0163] Therefore, it is possible to simultaneously achieve two effects: the characteristic of adjusting the adhesive strength of the silicone-based rubber membrane by the design of the closed concave portion and particle suppression.

[0164] (14th embodiment)

[0165] FIG. 19 shows a structural diagram of several examples of a microstructured stamp part (100) representing the 14th embodiment of the present invention.

[0166] In FIG. 19, 32 is a conductive silicone-based rubber membrane, and 33 to 36 are convex parts, showing various variations. Meanwhile, although not shown, the surface (32a) of the silicone-based rubber membrane (32) in FIG. 19(a), and the surfaces (33a, 34a, 35a and 36a) of the convex parts (33 to 36) in FIG. 19(b) to (f) have closed concave parts.

[0167] Meanwhile, in the convex portions (34 and 35) of FIG. 19(d) and (e), the cross-sectional shape of the convex projection at the final stage is shown to be in the shape of a horn.

[0168] The greatest feature of this embodiment is that the silicone-based rubber membrane (32) itself is a conductive membrane. To impart conductivity to the silicone-based rubber membrane, it can be achieved by mixing a carbon-based conductive membrane, such as carbon, carbon nanofiber, graphite, or graphene, as a filler.

[0169] Meanwhile, in FIG. 19, a conductive silicone-based rubber film (32) is formed in a limited area on the substrate (1), but a conductive silicone-based rubber film (32) may be formed on the entire surface of the substrate (1).

[0170] By configuring it in this way, it is possible to suppress particles generated during the transfer operation from adhering to the stamp part.

[0171] In the microstructured material-use stamp component described above in the embodiments of the present invention, the surface opening shape of the closed concave portion may be any shape that is closed, such as a circle, ellipse, ring, and polygon such as a triangle, rectangle (square, rectangular), square, pentagon, and hexagon.

[0172] Meanwhile, regarding the surface shape of the substrate and the silicone-based rubber film, while a square or rectangular shape is most convenient for processing, any shape such as a circle, ellipse, triangle, square, or hexagon may be used.

[0173] The formation of the silicone-based rubber membrane described above is described. A silicone-based rubber membrane having a flat membrane with closed concave portions and a silicone-based rubber membrane having a structure with a convex portion and closed concave portions on its surface can be formed, for example, by the imprint method. The curing reaction of the silicone-based rubber membrane may be thermal curing or UV curing.

[0174] Meanwhile, methods other than the imprint method may be used, and are not limited to the injection mold method; any method capable of forming the structure of the present invention may be used.

[0175] In the microstructured stamp component of the present invention, a quartz substrate can be used as the substrate. If a synthetic quartz substrate is used as the quartz substrate, performance is dramatically improved.

[0176] In the case of synthetic quartz substrates, total thickness variation (TTV) of approximately 1 μm or less can be achieved, thereby significantly improving the height uniformity of stamped parts compared to general quartz substrates. That is, when transferring multiple microstructures at once, all microstructures can be pressed more uniformly when the stamped parts are pressed on the supply substrate side and the receiving substrate side. More specifically, the timing of contact between the surface of the convex part formed on the surface of the silicone-based rubber film or silicone (applied)-based rubber film and the microstructure becomes more uniform, and their indentation depth becomes more uniform. Therefore, by using stamped parts made of synthetic quartz substrates, a more consistent adhesive strength can be secured for all multiple microstructures, thereby enabling stable transfer of microstructures. It goes without saying that this effect is also obtained when transferring a single microstructure from the convex part formed on the surface of the silicone-based rubber film or silicone (applied)-based rubber film.

[0177] Furthermore, the advantage of using synthetic quartz glass is that thermal stability is obtained. That is, synthetic quartz glass substrates have a coefficient of thermal expansion of approximately 1 / 5 compared to other quartz glass substrates, and can reduce thermal distortion during operation. In particular, in the case of stamp parts having convex protrusions, the misalignment and distortion of the protrusion position due to thermal expansion can be reduced, so it exerts its strength when performing repeated operation.

[0178] In addition, if a sapphire substrate is used instead of a quartz substrate, the mechanical strength is higher than that of a quartz (including synthetic quartz) substrate, so it is possible to provide a stamped component for microstructures with excellent durability. The in-plane uniformity of the sapphire substrate surface is 15 microns or less in TTV, so it is at a level where it can be sufficiently used as a substitute for a quartz substrate.

[0179] In addition, by using a silicon wafer or silicon wafer fragment instead of a quartz substrate, it is possible to provide a microstructured stamp component with superior flatness compared to a synthetic quartz substrate.

[0180] Meanwhile, when the size of the microstructure to be used is approximately several hundred μm or larger, if flatness is permissible, a glass substrate may be used instead of a quartz substrate.

[0181] Meanwhile, for silicone-based rubber membranes, compositions consisting of, for example, PDMS (Polydimethylsiloxane), a silicone composition in which the side chains and ends of PDMS are modified, and combinations thereof may be used. By adjusting the composition of each material (molecular weight, modifier group, modified substance, amount of modification, etc.) and, in the case of a mixture, the mixing ratio, physical properties such as the hardness, pressure adhesion, and repeatability of the material can be controlled. In addition to mixing, various modified silicone compositions can also be optimized by crosslinking or structuring the molecules in three dimensions.

[0182] Meanwhile, the transfer targets of the microstructure transfer stamp component of the present invention include, for example, semiconductor chips and various electrical (resistors, coils, capacitors, etc.) and electronic devices (diodes, transistors, thyristors, various high-performance LSI / IC chips, 3D mounting chips, SAW filter devices, MEMS chips such as accelerometers, and furthermore, LEDs, particularly miniLEDs or microLEDs, etc.), and the present invention is applicable to mounting these devices and assembly of electrical and electronic devices.

[0183] Meanwhile, the present invention is not limited to the above embodiments. The above embodiments are examples, and any configuration that is substantially identical to the technical concept described in the claims of the present invention and exhibits the same functional effects is included within the technical scope of the present invention.

Claims

Claim 1 A microstructured transfer stamp component having a rubber film on a substrate, wherein the surface of the rubber film opposite to the substrate has one or more convex portions, the convex portion has a first section and a second section along the height direction, the first section is located between the rubber film and the second section, the first section and the second section are frustums, the bottom surface on the substrate side of the frustum constituting the first section is larger than the bottom surface on the side opposite to the substrate side, and the bottom surface on the substrate side of the frustum constituting the second section is larger than the bottom surface on the side opposite to the substrate side. Claim 2 In claim 1, the frustum is a microstructure stamp part for Lee Jae-yong, which is a frustum of a cone or a frustum of a polygon. Claim 3 A microstructured stamp component according to claim 1, wherein the bottom surface opposite to the substrate side in the frustum constituting the first section is substantially the same size as the bottom surface on the substrate side in the frustum constituting the second section. Claim 4 In claim 1, the bottom surface opposite to the substrate side in the frustum constituting the first section is a microstructured stamp component larger than the bottom surface on the substrate side in the frustum constituting the second section. Claim 5 A microstructured stamp part according to claim 1, wherein the side of the truncated pyramid constituting the first section and the side of the truncated pyramid constituting the second section are connected to be convex toward the inside of the convex portion. Claim 6 A microstructured stamp part according to claim 1, wherein the side of the truncated pyramid constituting the first section and the side of the truncated pyramid constituting the second section are connected to be convex toward the outside of the convex portion. Claim 7 A microstructure stamp component according to claim 1, having a third section on the side opposite to the substrate side of the second section, wherein the third section is a frustum, and the bottom surface on the substrate side of the frustum constituting the third section is larger than the bottom surface on the side opposite to the substrate side. Claim 8 In claim 7, the bottom surface opposite to the substrate side in the frustum constituting the second section is substantially the same size as the bottom surface on the substrate side in the frustum constituting the third section, a microstructured material-use stamp component. Claim 9 In claim 7, the bottom surface opposite to the substrate side in the frustum constituting the second section is a microstructured stamp component larger than the bottom surface on the substrate side in the frustum constituting the third section. Claim 10 A microstructured stamp part according to claim 7, wherein the side of the truncated horn constituting the second section and the side of the truncated horn constituting the third section are connected to be convex toward the inside of the convex part. Claim 11 A convex part provided in a microstructure Lee Jae-yong stamp, having a shape formed by connecting two frustums, wherein the bottom surface with a smaller area in one frustum is connected to the bottom surface with a larger area in the other frustum, and the bottom surface with a smaller area in the one frustum is substantially the same size as the bottom surface with a larger area in the other frustum. Claim 12 A convex part provided in a microstructure Lee Jae-yong stamp, having a shape formed by connecting two frustums, wherein the bottom surface with a smaller area in one frustum is connected to the bottom surface with a larger area in the other frustum, and the bottom surface with a smaller area in the one frustum is larger than the bottom surface with a larger area in the other frustum. Claim 13 A transfer method characterized by transferring a microstructure using a microstructure transfer stamp part described in any one of claims 1 to 10. Claim 14 A method for manufacturing an electrical device having a process for transferring an electrical element using a microstructure transfer stamp component described in any one of claims 1 to 10. Claim 15 A method for manufacturing an electronic device having a process for transferring an electronic element using a microstructure transfer stamp component described in any one of claims 1 to 10. Claim 16 A method for manufacturing an LED display having a process for transferring an LED using a microstructure transfer stamp component described in any one of claims 1 to 10.

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