Stamp, holding part, transfer method, method for manufacturing electric / electronic application product, and method for manufacturing display

Abstract

Provided are a stamp, a stamp holding part, a transfer method using the stamp, a method for manufacturing an electric / electronic application product using the transfer method, and a method for manufacturing a display, which are capable of suppressing adhesion of a microstructure to a surface other than the stamp holding part, and in a case where a microstructure unintentionally adheres to the surface, of preventing the microstructure from falling off the stamp.　A stamp 100 for transferring a microstructure 200 includes: a base part 1 formed atop a substrate 10; a holding part 2 formed atop the base part 1 and having a holding surface 21 for holding the microstructure 200; and an adhesion suppression part 3 that is formed around the holding part 2 atop the base part 1 and that has a plurality of protrusions 4 having an adhesion suppression surface 41 lower in height than the holding surface 21. In a case where the microstructure 200 adheres to the adhesion suppression part 3, the adhesion suppression part 3 is formed to have an adhesion force such that the microstructure 200 does not come off under a force no more than the weight of the microstructure.

Description

Stamp, holding unit, transfer method, manufacturing method for electrical / electronic applied products, and manufacturing method for displays

[0001] The present invention relates to a stamp for transferring a microstructure such as a semiconductor element formed or arranged on a substrate to another substrate, a holder for the stamp, a transfer method using the stamp, a method for manufacturing an electrical / electronic applied product using the transfer method, and a method for manufacturing a display.

[0002] In recent years, with the miniaturization of semiconductor elements, microstructure transfer technology using stamps has attracted attention as a means of assembling electrical and electronic products using semiconductor elements. In particular, this technology has been actively developed to transfer one, multiple, or even tens of thousands of mini-LEDs (LEDs with short sides of 100 μm or more to several hundred μm) or micro-LEDs (with short sides of 100 μm or less, or even 50 μm or less) at a time, for use in signage, TVs, medical devices, in-vehicle devices, tablets, smartphones, smartwatches, and other displays, as well as for AR / VR.

[0003] The stamp has a convex holding portion 2 made of, for example, PDMS (polydimethylsiloxane) rubber. Microstructures can be attached to the holding portion 2 and transferred from a supply substrate to a receiving substrate. However, various conditions, such as pressure conditions, substrate thickness, dot height, stamp area, and improper height positioning of microLEDs, can lead to unintended attachment of microstructures to portions of the stamp other than the holding portion 2. Furthermore, microLEDs and other foreign matter, which can exist as contaminants in process environments such as cleaning solutions, can adhere to the stamp during handling. In particular, when microLEDs are attached, their relatively large contact area with the stamp makes them extremely difficult to remove by cleaning. Using a stamp with such attached microLEDs for re-picking can potentially damage the attached microLEDs by contacting new microLEDs. Furthermore, using a stamp with foreign matter attached can result in foreign matter adhering to the source microLED, the destination microLED, or the substrate, resulting in defects. Therefore, as shown in Figure 1, a small protrusion 49 has been proposed to prevent unintended attachment of microLEDs to portions other than the holding portion 2 (see, for example, Patent Document 1).

[0004] Patent No. 6453437

[0005] However, even if the surfaces of the stamp other than the holding part 2 are roughened, it is difficult to completely prevent microstructures from unintentionally adhering to parts of the stamp other than the holding part 2. On the other hand, if protrusions 49 are provided on the surfaces of the stamp other than the holding part 2, the attached microstructures will fall off the stamp before the stamp is washed, causing contamination of the transfer path, etc.

[0006] Therefore, the present invention aims to provide a stamp that can prevent microstructures from adhering to surfaces other than the holding part of the stamp, and that can prevent microstructures from falling off the stamp if they unintentionally adhere to such surfaces, a holding part for the stamp, a transfer method using the stamp, a method for manufacturing electrical and electronic application products using the transfer method, and a method for manufacturing displays.

[0007] In order to achieve the above-mentioned object, the stamp of the present invention is a stamp for transferring a microstructure, and comprises a base portion formed on a substrate, a holding portion formed on the base portion and having a holding surface for holding the microstructure, and an adhesion suppression portion formed around the holding portion on the base portion and having a plurality of convex portions with an adhesion suppression surface that is lower in height than the holding surface, and is characterized in that when the microstructure adheres to the adhesion suppression portion, the adhesion suppression portion is formed to have an adhesive strength that prevents the microstructure from coming off with a force less than its own weight.

[0008] In addition, the stamp of the present invention is a stamp for transferring a microstructure, and comprises a base portion formed on a substrate, a holding portion formed on the base portion and having a holding surface for holding the microstructure, and an adhesion suppression portion formed around the holding portion on the base portion and having a plurality of convex portions with an adhesion suppression surface that is lower in height than the holding surface, and is characterized in that the area B of the adhesion suppression surface is 1 / 100 or more times the area A of the holding surface.

[0009] In this case, it is preferable that the area B of the adhesion prevention surface is equal to or less than half the area A of the holding surface.

[0010] In addition, the stamp of the present invention is a stamp for transferring a microstructure, and comprises a base portion formed on a substrate, a holding portion formed on the base portion and having a holding surface for holding the microstructure, and an adhesion suppression portion formed around the holding portion on the base portion and having a plurality of convex portions with an adhesion suppression surface that is lower in height than the holding surface, and is characterized in that the adhesion suppression portion has a shape such that when a plane having the same shape as the holding surface comes into contact with the adhesion suppression portion at any position, the total contact area T between the plane and the adhesion suppression surface is 1 / 100 or more times the area A of the holding surface.

[0011] In this case, it is preferable that the adhesion prevention portion is shaped so that when the adhesion prevention portion comes into contact with a plane of the same shape as the holding surface at any position, the total contact area T between the plane and the adhesion prevention surface is less than 1 / 2 the area A of the holding surface.

[0012] The stamp of the present invention is a stamp for transferring a microstructure, and comprises: a base portion formed on a substrate; a holding portion formed on the base portion and having a holding surface for holding the microstructure; and an adhesion prevention portion formed around the holding portion on the base portion and having a plurality of convex portions with an adhesion prevention surface that is lower in height than the holding surface, wherein the adhesion prevention portion has a shape such that when the microstructure and the adhesion prevention surface come into contact at any position, the total contact area T' with the adhesion prevention surface is at least 1 / 100 times the area A' of the microstructure.

[0013] Here, it is preferable that the adhesion prevention portion has a shape such that when the microstructure and the adhesion prevention portion come into contact at any position, the total contact area T' with the adhesion prevention surface is at most 1 / 2 times the area A' of the microstructure.

[0014] In addition, the stamp of the present invention is a stamp for transferring a microstructure, and comprises a base portion formed on a substrate, a holding portion formed on the base portion and having a holding surface for holding the microstructure, and an adhesion suppression portion formed around the holding portion on the base portion and having a plurality of convex portions with an adhesion suppression surface that is lower in height than the holding surface, and is characterized in that the stamp has a shape such that the product of the adhesive strength of the material constituting the adhesion suppression surface and the area of ​​the adhesion suppression surface is 1 / 100 or more times the product of the adhesive strength of the material constituting the adhesion suppression portion and the area of ​​the adhesion suppression portion.

[0015] Here, it is preferable that the product of the adhesive strength of the material constituting the adhesion-inhibiting surface and the area of ​​the adhesion-inhibiting surface is 1 / 2 or less of the product of the adhesive strength of the material constituting the adhesion-retaining portion and the area of ​​the adhesion-retaining portion.

[0016] In addition, the stamp of the present invention is a stamp for transferring a microstructure, and is characterized in that it comprises a base portion formed on a substrate, and a holding portion formed on the base portion and having a holding surface for holding the microstructure, and has a plurality of convex portions on the side connecting the base portion and the holding surface, the convex portions having an adhesion-inhibiting surface that is lower in height than the holding surface.

[0017] Here, it is preferable that at least a portion of the holding portion has a cylindrical shape, a polygonal prism shape, a truncated cone shape, a truncated polygonal pyramid shape, or a shape obtained by chamfering any of these shapes.

[0018] Furthermore, the transfer method of the present invention can transfer a microstructure using the stamp of the present invention described above. Furthermore, the manufacturing method of an electrical / electronic application product of the present invention includes a step of transferring a microstructure by the transfer method. Furthermore, the manufacturing method of a display of the present invention includes a step of transferring a microstructure by the transfer method.

[0019] In addition, the holding portion of the present invention is a holding portion that is a component part of a stamp for transferring a microstructure, and is characterized in that it has a holding surface for holding the microstructure and a side extending toward the surface opposite the holding surface, and has a plurality of convex portions on the side having an adhesion-inhibiting surface.

[0020] In addition, the transfer method of the present invention is a transfer method for transferring a microstructure using a stamp, and includes a pick-up process for holding the microstructure on the holding surface of the stamp, and a detachment process for detaching the microstructure from the holding surface of the stamp, wherein the stamp comprises a base portion formed on a substrate, a holding portion formed on the base portion and having a holding surface for holding the microstructure, and an adhesion suppression portion formed around the holding portion on the base portion and having a plurality of convex portions with an adhesion suppression surface that is lower in height than the holding surface, and wherein when the microstructure adheres to the adhesion suppression portion, the adhesion suppression portion has an adhesive force that prevents it from coming off with a force less than the weight of the microstructure itself.

[0021] Here, it is preferable to have a removal step capable of removing the minute structures from the adhesion-preventing surface.

[0022] In addition, the transfer method of the present invention is a method for transferring microstructures using a stamp that picks up microstructures to be transferred and microstructures other than the target, wherein the stamp comprises a base portion formed on a substrate, a holding portion formed on the base portion and having a holding surface for holding the microstructure, and an adhesion suppression portion formed around the holding portion on the base portion and having a plurality of convex portions with adhesion suppression surfaces that are lower in height than the holding surface, and includes a pick-up process for holding the microstructure to be transferred in the holding portion, and a transfer process for transferring the microstructure to be transferred held in the holding portion, wherein the adhesive force of the adhesion suppression portion is controlled so that microstructures other than the target to be transferred are held in the adhesion suppression portion during the pick-up process, and the microstructures other than the target to be transferred held in the adhesion suppression portion continue to be held in the adhesion suppression portion during the transfer process.

[0023] Here, the method may further include a removal process for removing microstructures other than the transfer target that continue to be held in the adhesion prevention section, and may control the adhesive force of the adhesion prevention section or the removal force of the removal process so that the removal process removes microstructures other than the transfer target.

[0024] The method for manufacturing an electrical / electronic applied product of the present invention includes a step of transferring a microstructure by the transfer method of the present invention. The method for manufacturing a display of the present invention includes a step of transferring a microstructure by the transfer method.

[0025] The stamp for transferring microstructures, the holding part for the stamp, and the transfer method using the stamp of the present invention can prevent unintended detachment of microstructures in the event of unintended adhesion of the microstructures due to the structure of the adhesion prevention part.

[0026] 1A and 1B are a schematic cross-sectional view showing a conventional stamp, a schematic cross-sectional view showing a stamp of the present invention, a schematic plan view showing a stamp of the present invention, a schematic plan view showing a stamp of the present invention, and a schematic plan view showing another stamp of the present invention.

[0027] The stamp 100 of the present invention will be described below. As shown in Figures 2 and 3, the stamp 100 of the present invention is used to transfer a microstructure 200, and is composed of a base portion 1 formed on a substrate 10, a holding portion 2 having a holding surface 21 for holding the microstructure 200, and an adhesion prevention portion 3 having a plurality of protrusions 4 each having an adhesion prevention surface 41 that is lower in height than the holding surface 21.

[0028] Here, the term "microstructure 200" broadly refers to a minute object approximately several millimeters or less in size. Specifically, the microstructure 200 can be used for IC chips, one-dimensional to three-dimensional packages incorporating ICs and LSIs, inorganic or organic semiconductor elements such as light-emitting diodes (LEDs), and electrical circuit elements such as resistors, capacitors, and coils. These elements are too large for a conventional chip bonder to handle. In particular, there is a growing demand for LEDs with dimensions of several hundred micrometers or less. For LEDs, so-called mini-LEDs, whose short sides are 100 to several hundred micrometers, are currently available with heights of 100 to 130 micrometers. For so-called micro-LEDs with short sides less than 100 micrometers, or even 50 micrometers or less, the sapphire substrate layer is removed, resulting in a thickness of 6 micrometers. In such cases, the in-plane variation of the surface of the stamp component 13 that adheres to the microstructure 200 is preferably approximately several times the thickness (height) of the LED. Furthermore, even micro-objects other than electrical and electronic circuit elements that cannot be directly grasped by vacuum suction can be arbitrarily transferred and assembled using the micro-structure transfer device of the present invention, and become the micro-structure 200 that is the transfer target of the present invention.

[0029] The base portion 1 is formed on a substrate 10 and serves as the foundation for the holding portion 2 and adhesion prevention portion 3 described below. The base portion 1 may be made of any material as long as it serves as the foundation for the holding portion 2 and adhesion prevention portion 3, but examples include resins such as silicone rubber and PDMS (polydimethylsiloxane) rubber.

[0030] If the base portion 1 is too thick, when the holder 2 is deformed, microstructures 200 other than the transfer target are likely to come into contact with the base portion 1. Furthermore, when pressure is applied, the substrate 10 and base portion 1 are likely to deform convexly on the side opposite the pressure direction, which also makes it easier for microstructures 200 other than the transfer target to come into contact with the base portion 1. These can cause unintended adhesion of microstructures 200. Therefore, the height of the base portion 1 should be no more than three times the height of the holder 2, preferably no more than one time, and more preferably no more than one-half time.

[0031] The substrate 10 is the base of the base portion 1. The substrate 10 can be made of any material that can serve as the base of the base portion 1, including, for example, a quartz glass substrate. The quartz glass substrate is preferably synthetic quartz glass. When the size of the microstructure 200 is small, with a height of less than several tens of micrometers, the flatness of the base portion 1, which serves as the base for the holder 2, becomes important. It is preferable that this flatness vary within approximately the height of the microstructure 200. The flatness of the base portion 1, such as a silicone rubber film, is greatly influenced by the flatness of its substrate, the quartz glass substrate. Synthetic quartz glass can achieve a total thickness variation (TTV) of approximately 1 μm or less, so using synthetic quartz glass minimizes the thickness variation across the entire stamp component. Another advantage of using synthetic quartz glass is its thermal stability during repeated microstructure transfer operations. That is, a synthetic quartz glass substrate has a thermal expansion coefficient that is approximately one-fifth that of other quartz glass substrates, allowing for reduced thermal distortion during operation. In particular, in the case of a stamp 100 having a holder 2, it is possible to reduce displacement and distortion of the holding surface 21 of the holder 2 due to thermal expansion and contraction, enabling accurate transfer operations. The substrate 10 may be formed integrally with the base 1, etc. For example, the substrate 10, holder 2, and adhesion prevention part 3 can all be molded together from resin.

[0032] The holding unit 2 is formed on the base unit 1 and has a holding surface 21 for holding the microstructure 200. The number of holding units 2 on the base unit 1 may be one or more. When one holding unit 2 is arranged on the base unit 1, one of the microstructures 200 densely arranged on the supply substrate can be selectively attached to the holding surface 21, picked up, and placed at any position on the receiving substrate. This can be used for repair, in which a normal microstructure 200 is selectively transferred to the position of a defective microstructure 200. On the other hand, when multiple holding units 2 are arranged on the base unit 1, multiple microstructures 200 corresponding to the positions of the holding units 2 can be transferred at once.

[0033] The shape of the holder 2 may be any shape as long as it can hold the microstructure 200, and may be appropriately designed so as to optimally hold the microstructure 200 in accordance with the shape and size of the microstructure 200. For example, at least a portion of the holder 2 may be a columnar shape such as a cylindrical shape or a polygonal prism shape, a truncated cone shape such as a truncated cone shape or a truncated polygonal pyramid shape, or a shape with a partially chamfered edge, or a combination of these shapes.

[0034] Furthermore, if the distance between the holders 2 is large, microstructures 200 other than those to be transferred are likely to come into contact with the base 1 when the holders 2 are deformed, which may result in unintended adhesion of the microstructures 200. Therefore, it is preferable to separate the holders 2 by a distance of at least 1 / 2 the height of the holders 2, preferably 1 time or more, and more preferably 2 times or more.

[0035] Furthermore, if a microstructure 200 other than the target to be transferred is unintentionally attached to the protrusion 4 of the adhesion prevention unit 3, a low height of the holding unit 2 will hinder the transfer of the target microstructure 200. Therefore, it is advisable to form the holding unit 2 to have a height at least twice the total height of the protrusion 4 and the thickness of the microstructure 200, preferably three times or more, and more preferably five times or more.

[0036] The material of the holder 2 may be any material that can hold the microstructure 200 without damaging it, and examples of such materials include resins such as silicone rubber and PDMS (polydimethylsiloxane) rubber. The holder 2 and the base 1 may be formed from different materials, or may be formed integrally from the same material.

[0037] The holding surface 21 is a surface provided on the side of the holding unit 2 facing the base unit 1, and is used to hold the microstructure 200 by the adhesive force of this surface. The holding surface 21 is capable of direct contact with the microstructure 200, thereby holding the microstructure 200. The shape of the holding surface 21 may be any shape as long as it can hold the microstructure 200, and it may be designed appropriately to exert optimal adhesive force for the shape and size of the microstructure 200. For example, if the surface of the microstructure 200 held by the holding surface 21 (hereinafter referred to as the held surface 201) is rectangular in plan view, the holding surface 21 can be formed into a rectangle to match that. Furthermore, the holding surface 21 is not limited to a flat surface.

[0038] The adhesion prevention portion 3 is a region formed around the holding portion 2 on the base portion 1. The adhesion prevention portion 3 also has a plurality of convex portions 4 each having an adhesion prevention surface 41 that is lower in height than the holding surface 21. This makes it possible to prevent the microstructure 200 from adhering to the base portion 1. The adhesion prevention portion 3 may be made of any material, including, for example, resins such as silicone rubber and PDMS (polydimethylsiloxane) rubber. The adhesion prevention portion 3 and the base portion 1 may be made of different materials, or may be integrally formed from the same material.

[0039] The adhesion-preventing surface 41 may be any surface, whether flat or curved, that can prevent adhesion of the microstructure 200. In order to prevent adhesion of the microstructure 200, the adhesion-preventing portion 3 is formed so that its adhesive strength with the microstructure 200 is weaker than that of the holding surface 21. For example, the adhesion-preventing portion 3 is formed to have a plurality of protrusions 4 so that the area that adheres to the microstructure 200 is smaller than that of the holding surface 21.

[0040] On the other hand, it is preferable that the adhesion prevention unit 3 not only prevents the microstructure 200 from adhering, but also prevents the microstructure 200 from falling off the stamp 100 into the transfer path or the like due to its own weight or the like once it has adhered to the adhesion prevention unit 3, as shown in Figure 3. For this purpose, it is preferable that the adhesion prevention unit 3 is formed so as to have an adhesive strength that prevents the microstructure 200 from coming off with a force at least equal to or less than the weight of the microstructure 200 when the microstructure 200 adheres to the adhesion prevention unit 3. Various design methods can be considered for such an adhesion prevention unit 3, taking into consideration the microstructure 200 to be transferred. For example, it may be designed as follows.

[0041] (1) When the area A of the holding surface 21 is determined based on the weight of the microstructure 200 to be held, the area B of the adhesion-preventing surface 41 can be designed using the ratio to the area A of the holding surface 21. The inventors discovered that to stably hold the microstructure 200, the adhesive energy of the holding surface must be at least 100 times the adhesive energy required to hold the microstructure 200. Therefore, when the holding surface 21 and the adhesion-preventing surface 41 are formed of the same material, in order to prevent the microstructure 200 from falling off the stamp 100 once attached, the area B of the adhesion-preventing surface 41 should be at least 1 / 100 times, preferably at least 1 / 50 times, and more preferably at least 1 / 30 times the area A of the holding surface 21. Furthermore, in order to prevent the microstructure 200 from adhering to the adhesion-preventing unit 3, the area B of the adhesion-preventing surface 41 should be at most 1 / 2 times, preferably at most 1 / 5 times, and more preferably at most 1 / 10 times the area A of the holding surface 21.

[0042] (2) Furthermore, since the shape of the holding surface 21 is generally formed to match the shape of the microstructure 200 to be held, it can also be designed based on that shape. For example, as shown in FIG. 4 , when a virtual flat surface 300 having the same shape as the holding surface 21 and the adhesion prevention surface 41 come into contact with the adhesion prevention unit 3 at an arbitrary position, the adhesion prevention unit 3 can be designed using the ratio of the total contact area T between the flat surface 300 and the adhesion prevention surface 41 to the area A of the holding surface 21. To prevent the microstructure 200 from falling off the stamp 100 once attached, the adhesion prevention unit 3 should be shaped so that the total contact area T is 1 / 100 times or more, preferably 1 / 50 times or more, and more preferably 1 / 30 times or more of the area A of the holding surface 21. To prevent the microstructure 200 from adhering to the adhesion prevention unit 3, the adhesion prevention unit 3 should be shaped so that the total contact area T is 1 / 2 times or less, preferably 1 / 5 times or less, and more preferably 1 / 10 times or less of the area A of the holding surface 21. The total contact area T can be adjusted by adjusting the number and arrangement of the protrusions 4 of the adhesion prevention portion 3 and the shape and area of ​​the adhesion prevention surface 41.

[0043] (3) The adhesion prevention unit 3 can also be designed based on the area A' of the held surface 201 of the microstructure 200. As shown in FIG. 3 , the adhesion prevention unit 3 can be designed using the ratio of the total contact area T' between the held surface 201 and the adhesion prevention surface 41 to the area A' of the microstructure 200 when the microstructure 200 and the adhesion prevention unit 3 come into contact at any position. For example, in order to prevent the microstructure 200 from falling off the stamp 100 once it has adhered, the adhesion prevention unit 3 should be shaped so that the total contact area T' is 1 / 100 times or more, preferably 1 / 50 times or more, and more preferably 1 / 30 times or more of the area A' of the microstructure 200. In addition, in order to prevent the microstructure 200 from adhering to the adhesion prevention unit 3, the adhesion prevention unit 3 should be shaped so that the total contact area T' is 1 / 2 times or less, preferably 1 / 5 times or less, and more preferably 1 / 10 times or less of the area A' of the microstructure 200. The total contact area T' can be adjusted by adjusting the number of protrusions 4 of the adhesion prevention portion 3 and the shape and area of ​​the adhesion prevention surface 41.

[0044] (4) The adhesion-preventing surface 41 may be made of a material different from that of the holding surface 21. In this case, the adhesion-preventing surface 41 may be designed using the ratio of the product of the adhesive strength and the contact area of ​​the materials that make up the holding surface 21 and the adhesion-preventing surface 41. The adhesive strength of the materials that make up the holding surface 21 and the adhesion-preventing surface 41 may be P Ａ , P Ｂ Then, in order to prevent the minute structure 200 once attached from falling off the stamp 100, P Ａ ×A is P Ｂ ×B is preferably 1 / 100 times or more, more preferably 1 / 50 times or more, and even more preferably 1 / 30 times or more. Ａ ×A is P Ｂ It is preferable to form it to be 1 / 2 times or less of xB, preferably 1 / 5 times or less, and more preferably 1 / 10 times or less.

[0045] The adhesive strength of the material constituting the support surface 21 and adhesion-preventing surface 41 is measured as follows. First, a sample is formed by placing the material constituting the support surface 21 or adhesion-preventing surface 41 in an aluminum dish to a thickness of 1 mm. The sample surface is formed so that it is approximately horizontal. Furthermore, because the surface texture of the sample affects the adhesive strength, the sample must be kept smooth and free of air bubbles, large irregularities, or slopes. The sample surface (adhesive surface) must be kept free of dust, and the adhesive surface must not be touched or have foreign matter attached, even during measurement. Next, in an environment of 23°C and 50% RH (relative humidity), double-sided adhesive tape (Nitto Denko Corporation, product name: general-purpose double-sided tape No. 501F) is affixed to the back of the aluminum dish and securely fixed to the lower pressure plate, which serves as the sample stage of a Shimadzu EZ-SX compact benchtop testing machine. A 1 mm square SUS probe attached to the testing machine was pressed downward perpendicular to the surface (adhesive surface) of the sample. This pressing was performed by contacting the probe with the adhesive surface at a speed of 0.05 mm / sec, followed by a contact load of 1 MPa for 15 seconds. The probe was then moved in the opposite direction to the pressing, from bottom to top at a speed of 200 mm / min perpendicular to the surface (adhesive surface). The force required to peel the probe from the sample surface was measured, and the maximum measured value was taken as the adhesive strength. Measurements were performed five times for each sample, and the average adhesive strength value for each measurement was used as the adhesive strength in this invention. Note that the influence of the probe's surface texture on adhesive strength cannot be ignored in this measurement. Therefore, the material was SUS304, and the surface roughness was limited to approximately 250-500 nm in root mean square roughness (Rq).

[0046] It is also possible to form a plurality of protrusions 5 having adhesion prevention surfaces 51 on the side surface 25 connecting the base portion 1 and the holding surface 21. In this case, the height of the adhesion prevention surfaces 51 of the protrusions 5 is formed lower than the height of the holding surface 21. This makes it possible to prevent the microstructure 200 from accidentally adhering to the side surface 25 of the holding portion 2 when holding the microstructure 200 on the holding surface 21.

[0047] Next, a transfer method of the present invention will be described. The transfer method of the present invention is a method for transferring a microstructure 200 using a stamp, and is mainly composed of a pick-up step and a release step. The stamp 100 of the present invention described above can be used as the stamp. For example, a stamp can be used that includes a base portion 1 formed on a substrate 10, a holding portion 2 formed on the base portion 1 and having a holding surface 21 for holding the microstructure 200, and an adhesion prevention portion 3 formed around the holding portion 2 on the base portion 1 and having a plurality of protrusions 4 with an adhesion prevention surface 41 that is lower in height than the holding surface 21. When the microstructure 200 adheres to the adhesion prevention portion 3, the adhesion prevention portion 3 has an adhesive strength that prevents the adhesion prevention portion 3 from coming off with a force less than the weight of the microstructure 200.

[0048] The pick-up process is a process of bringing the microstructure 200 into contact with the holding surface 21 of the stamp and holding it. For example, the holding surface 21 of the stamp is brought into contact with one or more of the microstructures 200 arranged in large quantities on a supply substrate, and pressure is applied to adhere the microstructures 200 to the holding surface 21. Next, by separating the stamp from the supply substrate, the microstructures 200 can be picked up and held on the holding surface 21 of the stamp.

[0049] The detachment process is a process of detaching the microstructure 200 from the holding surface 21 of the stamp. The detachment process may be performed by any method as long as it is possible to detach the microstructure 200 from the holding surface 21 of the stamp. For example, a film having an adhesive force greater than the adhesive force of the holding surface 21 of the stamp is formed on the receiving substrate. Then, in the pick-up process, the microstructure 200 held on the holding surface 21 of the stamp is pressed onto the receiving substrate. Subsequently, the stamp and the receiving substrate are separated, thereby making it possible to detach the microstructure 200 held on the holding surface 21 of the stamp.

[0050] It is also preferable to have a removal process capable of removing the microstructure 200 from the adhesion-inhibited surface 41. The removal process may be carried out in any manner as long as it is possible to remove the microstructure 200 from the adhesion-inhibited surface 41, and for example, wet cleaning or dry cleaning may be performed. For example, wet cleaning may involve immersing the stamp in an isopropanol bath and applying ultrasonic waves. For example, dry cleaning may involve immersing the stamp in supercritical CO ２ By this, the minute structure 200 adhering to the adhesion prevention surface 41 can be removed.

[0051] Another transfer method of the present invention is a method for transferring a microstructure 200 using a stamp that picks up a microstructure 200 to be transferred and a microstructure 200 other than the microstructure 200 to be transferred, and is mainly composed of a pick-up process and a transfer process. The stamp can be the stamp 100 of the present invention described above. For example, a stamp can be used that includes a base portion 1 formed on a substrate 10, a holding portion 2 formed on the base portion 1 and having a holding surface 21 for holding the microstructure 200, and an adhesion suppression portion 3 formed around the holding portion 2 on the base portion 1 and having a plurality of protrusions 4 with an adhesion suppression surface 41 that is lower in height than the holding surface 21.

[0052] The pick-up process is a process of holding the microstructure 200 to be transferred on the holding part 2. For example, the holding surface 21 of the stamp is brought into contact with one or more of the microstructures 200 arranged in large quantities on a supply substrate, and pressure is applied to adhere the microstructures 200 to the holding surface 21. Next, by separating the stamp from the supply substrate, the microstructures 200 can be picked up and held on the holding surface 21 of the stamp.

[0053] The transfer step is a step of transferring the microstructure 200 to be transferred that is held by the holding unit 2. For example, after picking up the microstructure 200 from a supply substrate, the microstructure 200 held by the holding unit 2 is transferred from the supply substrate to a receiving substrate, and the microstructure 200 is placed on the receiving substrate.

[0054] Here, when a microstructure 200 other than the transfer target is held by the adhesion prevention unit 3 during the pick-up process, the adhesive force of the adhesion prevention unit 3 is controlled so that the microstructure 200 other than the transfer target held by the adhesion prevention unit 3 continues to be held by the adhesion prevention unit 3 during the transfer process. The adhesive force can be controlled, for example, by adjusting the adhesive force of the adhesion prevention surface, or, as in the stamp 100 of the present invention described above, by adjusting the number of protrusions 4 of the adhesion prevention unit 3 or the shape and area of ​​the adhesion prevention surface 41.

[0055] The method may further include a removal step of removing the microstructures 200 other than the transfer target that have been held by the adhesion prevention unit 3. In this case, the adhesive force of the adhesion prevention unit 3 or the removal force of the removal step is controlled so that the microstructures 200 other than the transfer target are removed by the removal step. The removal step may be performed in any manner as long as it is possible to remove the microstructures 200 from the adhesion prevention surface 41, and for example, wet cleaning or dry cleaning may be performed.

[0056] The above-described transfer method of the present invention can be applied to a manufacturing method of an electric / electronic applied product, which includes a step of transferring a microstructure by the transfer method. Also, the above-described transfer method of the present invention can be applied to a manufacturing method of a display, which includes a step of transferring a microstructure by the transfer method.

[0057] REFERENCE SIGNS LIST 1 base portion 2 holding portion 3 adhesion-inhibiting portion 4 convex portion 5 convex portion 10 substrate 21 holding surface 25 side surface 41 adhesion-inhibiting surface 51 adhesion-inhibiting surface 100 stamp 200 microstructure 300 flat surface

Claims

1. A stamp for transferring a microstructure, comprising: a base portion formed on a substrate; a holding portion formed on the base portion and having a holding surface for holding the microstructure; and an adhesion prevention portion formed around the holding portion on the base portion and having a plurality of convex portions with an adhesion prevention surface that is lower in height than the holding surface, wherein when the microstructure adheres to the adhesion prevention portion, the adhesion prevention portion is formed to have an adhesive strength that prevents the microstructure from coming off with a force less than its own weight.

2. A stamp for transferring a microstructure, comprising: a base portion formed on a substrate; a holding portion formed on said base portion and having a holding surface for holding said microstructure; and an adhesion prevention portion formed around said holding portion on said base portion and having a plurality of convex portions with an adhesion prevention surface that is lower in height than said holding surface, wherein area B of said adhesion prevention surface is 1 / 100 or more times area A of said holding surface.

3. The stamp according to claim 2, wherein the area B of the adhesion-inhibiting surface is 1 / 2 or less of the area A of the holding surface.

4. A stamp for transferring a microstructure, comprising: a base portion formed on a substrate; a holding portion formed on said base portion and having a holding surface for holding said microstructure; and an adhesion suppression portion formed around said holding portion on said base portion and having a plurality of convex portions with an adhesion suppression surface that is lower in height than said holding surface, wherein said adhesion suppression portion is shaped so that when a flat surface having the same shape as said holding surface comes into contact with said adhesion suppression portion at any position, the total contact area T between said flat surface and said adhesion suppression surface is 1 / 100 or more times the area A of said holding surface.

5. A stamp as described in claim 4, characterized in that the adhesion prevention portion is shaped so that when the adhesion prevention portion comes into contact with a plane of the same shape as the holding surface at any position, the total contact area T between the plane and the adhesion prevention surface is less than 1 / 2 the area A of the holding surface.

6. A stamp for transferring a microstructure, comprising: a base portion formed on a substrate; a holding portion formed on said base portion and having a holding surface for holding said microstructure; and an adhesion suppression portion formed around said holding portion on said base portion and having a plurality of convex portions with an adhesion suppression surface that is lower in height than said holding surface, wherein said adhesion suppression portion is shaped so that when said microstructure and said adhesion suppression portion come into contact at any position, the total contact area T' with said adhesion suppression surface is 1 / 100 or more times the area A' of said microstructure.

7. A stamp as described in claim 6, characterized in that the adhesion prevention portion is shaped so that when the microstructure and the adhesion prevention portion come into contact at any position, the total contact area T' with the adhesion prevention surface is less than 1 / 2 the area A' of the microstructure.

8. A stamp for transferring a microstructure, comprising: a base portion formed on a substrate; a holding portion formed on said base portion and having a holding surface for holding said microstructure; and an adhesion-inhibiting portion formed around said holding portion on said base portion and having a plurality of convex portions with an adhesion-inhibiting surface that is lower in height than said holding surface, wherein the product of the adhesive strength and area of ​​said adhesion-inhibiting surface is 1 / 100 or more times the product of the adhesive strength and area of ​​said holding surface.

9. The stamp according to claim 8, wherein the product of the adhesive strength and area of ​​said adhesion-inhibiting surface is 1 / 2 or less of the product of the adhesive strength and area of ​​said holding surface.

10. A stamp for transferring a microstructure, comprising: a base portion formed on a substrate; and a holding portion formed on the base portion and having a holding surface for holding the microstructure, characterized in that the stamp has a plurality of convex portions on the side connecting the base portion and the holding surface, the convex portions having an adhesion-inhibiting surface that is lower in height than the holding surface.

11. The stamp according to claim 9, wherein at least a portion of said holding portion is in the shape of a cylinder, a polygonal prism, a truncated cone, a truncated polygonal pyramid, or a shape obtained by chamfering any of these.

12. A holding part that is a component of a stamp for transferring a microstructure, comprising a holding surface for holding the microstructure and a side extending toward the surface opposite the holding surface, and characterized in that the side has a plurality of protrusions with adhesion-inhibiting surfaces.

13. A transfer method for transferring a microstructure using a stamp, comprising: a pick-up step of holding the microstructure on the holding surface of the stamp; and a detachment step of detaching the microstructure from the holding surface of the stamp, wherein the stamp comprises a base portion formed on a substrate, a holding portion formed on the base portion and having a holding surface for holding the microstructure, and an adhesion suppression portion formed around the holding portion on the base portion and having a plurality of convex portions with an adhesion suppression surface that is lower in height than the holding surface, and wherein when the microstructure adheres to the adhesion suppression portion, the adhesion suppression portion has an adhesive strength that prevents it from coming off with a force less than the weight of the microstructure itself.

14. The transfer method according to claim 13, further comprising a removal step capable of removing the minute structure from the adhesion-inhibiting surface.

15. A method for transferring a microstructure using a stamp that picks up a microstructure to be transferred and a microstructure other than the target, wherein the stamp comprises a base portion formed on a substrate, a holding portion formed on the base portion and having a holding surface for holding the microstructure, and an adhesion suppression portion formed around the holding portion on the base portion and having a plurality of convex portions with an adhesion suppression surface that is lower in height than the holding surface, the method comprising a pick-up process for holding the microstructure to be transferred in the holding portion, and a transfer process for transferring the microstructure to be transferred held in the holding portion, wherein during the pick-up process, the microstructure other than the target to be transferred is held in the adhesion suppression portion, and the adhesive force of the adhesion suppression portion is controlled so that the microstructure other than the target to be transferred held in the adhesion suppression portion continues to be held by the adhesion suppression portion during the transfer process.

16. A transfer method as described in claim 15, further comprising a removal process for removing microstructures other than the transfer target that have been held by the adhesion prevention unit, and controlling the adhesive force of the adhesion prevention unit or the removal force of the removal process so that the microstructures other than the transfer target are removed by the removal process.

17. A transfer method comprising transferring a minute structure using the stamp according to any one of claims 1 to 11.

18. A method for manufacturing an electric / electronic applied product, comprising a step of transferring a minute structure by the transfer method according to claim 17.

19. A method for manufacturing an electrical / electronic applied product, comprising a step of transferring a microstructure by the transfer method according to any one of claims 13 to 16.

20. A method for manufacturing a display, comprising a step of transferring a minute structure by the transfer method according to claim 17.

21. A method for manufacturing a display, comprising a step of transferring a minute structure by the transfer method according to any one of claims 13 to 16.

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