A cavity-column combined shape memory polymer stamp and a microchip proximity type transfer method thereof

Abstract

The application discloses a cavity-column combined shape memory polymer stamp and a microchip proximity transfer method thereof. The stamp takes shape memory epoxy resin as a matrix, and a cavity-column combined structure is directly formed through laser microprocessing. The stamp realizes an adhesion switching ratio of up to 1200 by utilizing the change of the elastic modulus of the cavity-column combined shape memory polymer stamp before and after the glass transition temperature, and realizes the low-cost microchip high-precision proximity transfer of high-adhesion pickup and low-adhesion release by combining negative pressure auxiliary adsorption and micro-column directional pushing. The stamp has simple preparation process, does not need complex photoetching process, and can be flexibly regulated and controlled according to the performance requirements of the stamp. The stamp can be adapted to silicon, polyimide, copper, glass, acrylic and other material chips with roughness of 1nm-500nm. The maximum strain of the stamp is only 0.27 during the transfer process, the interface temperature is controllable, the residual adhesion strength is small, and the problems of the existing transfer technology, such as complex preparation, narrow application range and low transfer reliability, are solved.

Description

Technical Field

[0001] This invention belongs to the field of flexible electronics manufacturing, specifically relating to a cavity-pillar combined shape memory polymer stamp and its microchip proximity transfer method. Background Technology

[0002] Microchip transfer technology is one of the core processes in fields such as flexible electronics and microdevice integration. Its core requirements are efficient chip pickup, precise transfer, and non-destructive release. However, achieving high efficiency, high precision, and high yield simultaneously is challenging for microchip transfer. Existing transfer technologies can be mainly categorized based on the forces and methods used during the transfer process: van der Waals force transfer, roll-to-roll roller transfer, and fluid self-assembly transfer. However, these methods cannot simultaneously achieve adjustable adhesion strength, high-precision transfer, and efficient pickup. In contrast, laser-assisted transfer technology, through patterned laser spots, controls the transfer process, offering advantages such as good programmability, high processing speed, and good controllability.

[0003] For laser-assisted transfer technology, methods such as laser-induced bubble-assisted transfer and laser thermal stress-assisted transfer technology have been proposed.

[0004] However, the above methods may have problems such as difficulty in guaranteeing transfer accuracy, potential thermal damage to the microchip, or the inability to reuse the transfer device. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a cavity-pillar combined shape memory polymer stamp and its microchip proximity transfer method. The stamp is directly formed using laser processing, significantly simplifying the manufacturing process and reducing costs, resulting in a composite structure with micropillars within a cavity. When picking up the microchip, the stamp offers the advantage of regionally adjustable adhesion strength. Furthermore, the cavity structure not only protects the micropillars, but the negative pressure created by thermal changes further enhances the pickup adhesion strength. Upon release, because the original length of the micropillars exceeds the cavity depth, the directional pushing of the micropillars allows for high-precision proximity transfer during shape recovery. This improves the stamp's mechanical stability while achieving high-precision, high adhesion switching ratio, and low-cost transfer of the microchip.

[0006] The specific technical solution for achieving the objective of this invention is as follows:

[0007] A cavity-pillar bonded shape memory polymer stamp includes a substrate, cavity-pillar bonded units, a polyimide substrate layer, and a transparent quartz substrate;

[0008] The cavity-column bonding unit is made of shape memory polymer and is disposed on one side of the substrate;

[0009] On the other side of the substrate, a polyimide substrate layer and a transparent quartz substrate are sequentially disposed;

[0010] A carbon layer is disposed on the surface of the polyimide substrate layer;

[0011] The cavity column unit is used to adsorb the workpiece to be transferred, and the polyimide substrate and the transparent quartz substrate work together with a laser to regulate the temperature of the stamp.

[0012] Furthermore, the cavity-column bonding unit includes a uniformly arranged array of micropillars, and each micropillar in the array is independently disposed in a uniformly arranged cavity.

[0013] The height of the micropillar is greater than the depth of the cavity.

[0014] Furthermore, the shape memory polymer is a shape memory epoxy resin, which is composed of epoxy resin and curing agent in a certain mass ratio.

[0015] Furthermore, the fabrication process of the cavity-column bonding unit includes:

[0016] Preparation of shape memory polymer substrates:

[0017] After mixing epoxy resin E44 and curing agent D230 at a mass ratio of 1:0.35~1:0.65, vacuum evacuation is performed. The mixture solution is poured into a PDMS mold and sealed with a polyimide substrate with a carbon layer and a transparent quartz substrate. Then it is cured at 90°C on a hot plate and then demolded to complete the preparation of the shape memory polymer substrate.

[0018] Fabrication of micropillar arrays and cavities with cavity-pillar bonding units on shape memory polymer substrates:

[0019] A 355nm ultraviolet picosecond laser was used to selectively cut the surface of a shape memory polymer substrate. The cutting was performed in two stages. In the first stage, a micropillar array was cut out. Using preset laser parameters, a layer was removed from the entire surface of the shape memory polymer substrate except for the reserved micropillar array positions, forming a micropillar array with a certain height on the surface of the shape memory polymer substrate. In the second stage, a cavity was cut out. According to preset laser parameters, the cavity was cut at the annular position at the edge of the micropillars, ultimately forming a cavity-pillar combined unit with a micropillar height higher than the cavity edge, thus completing the stamp fabrication.

[0020] Furthermore, the laser scanning path adopts a horizontal and vertical path.

[0021] Furthermore, the preparation process of the polyimide substrate layer includes:

[0022] After a non-photosensitive polyimide precursor solution was spin-coated onto a transparent quartz substrate for a certain period of time, the substrate was heated on a hot plate. After spin-coating and curing multiple layers, the substrate was heated at 220°C for 4 hours to prepare a 15μm thick polyimide film.

[0023] The energy utilized is 222 mJ / cm 2 A 308nm excimer laser irradiates a polyimide film 1000 times through a transparent quartz substrate. The polyimide film irradiated by the excimer laser absorbs the laser energy and carbonizes to form a carbonized layer to enhance the absorption of infrared laser. After 12 hours of rest, the internal gas escapes and the polyimide film flattens out.

[0024] This solution also provides a microchip proximity transfer method using the above-mentioned cavity-column combined shape memory polymer stamp, including the following steps:

[0025] (1) Pick-up phase:

[0026] Align one side of the cavity-pillar bonding unit of the cavity-pillar bonding type shape memory polymer stamp with the target chip on the donor substrate, and apply a certain pre-pressure to make the cavity-pillar bonding unit fit tightly with the surface of the target chip.

[0027] Maintaining pre-pressure, heating causes the temperature of the cavity-pillar bonding unit to exceed its glass transition temperature. At this point, the elastic modulus of the cavity-pillar bonded shape memory polymer stamp decreases, causing it to deform under pressure. The micropillar contacts the target chip and is compressed into the cavity by the target chip, increasing the contact area between the cavity-pillar bonded shape memory polymer stamp and the target chip, thus enhancing adhesion strength. After cooling, the stamp temperature is lowered below the glass transition temperature and it is shaped. At this point, the cavity-pillar bonded shape memory polymer stamp and the target chip still maintain a high contact area and high adhesion strength. Simultaneously, the cavity generates negative pressure after the heating and cooling process, further enhancing the adhesion strength to the target chip. The target chip leaves the donor substrate, at which point the pickup adhesion strength is greater than 20 kPa.

[0028] (2) Transfer phase:

[0029] While maintaining the picking state, move the stamp with the target chip attached to it above the recipient substrate and adjust the gap between the stamp and the recipient substrate to a preset distance.

[0030] (3) Release phase:

[0031] An 808nm infrared laser is used to irradiate a cavity-pillar bonded shape memory polymer stamp from one side of a transparent quartz substrate. The carbon layer of the polyimide substrate absorbs the 808nm infrared laser, generating heat. This heat is transferred to the cavity-pillar bonded unit, raising its temperature above the glass transition temperature. The cavity-pillar bonded unit of the cavity-pillar bonded shape memory polymer stamp returns to its original shape, reducing the contact area with the target chip. The negative pressure disappears, and the residual adhesion strength is less than 0.1kPa. At the same time, the micropillars return to their original height. Under the directional push generated when the micropillars return to their original height and the action of their own gravity, the target chip adheres to the recipient substrate, completing the proximity transfer.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] (1) Simple fabrication process: The cavity column structure is directly formed by laser micromachining, without the need for complex processes such as photolithography and casting, resulting in a short processing cycle and low cost.

[0034] (2) Adhesion strength is adjustable and has excellent performance: The micro-pillar structure achieves regional adjustment of adhesion strength through point contact. The cavity structure forms negative pressure after the change of temperature, which further enhances the pickup adhesion strength. The pickup adhesion strength is large and the residual adhesion strength is small. The switching ratio can reach 1200.

[0035] (3) Good mechanical properties and high transfer accuracy: laser-induced heating is precisely controlled, the maximum strain of the SMP stamp is only 0.27, which is less than the ultimate compressive strain of 0.73, avoiding structural damage. In addition, combined with the directional pushing effect when the micro-pillar recovers its deformation, it achieves proximity transfer, so that the chip can maintain the shape and pattern before the transfer to the maximum extent after the transfer.

[0036] The present invention will be further described below with reference to specific embodiments. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the cavity-column combined shape memory polymer stamp structure of the present invention.

[0038] Figure 2 This is a schematic diagram of the method for preparing a polyimide substrate with a carbon layer according to the present invention.

[0039] Figure 3 This is a schematic diagram of the method for preparing the cavity-column combined shape memory polymer stamp of the present invention.

[0040] Figure 4 This is a schematic diagram of the microchip proximity transfer method using a cavity-pillar combined shape memory polymer stamp according to the present invention. Detailed Implementation

[0041] Example

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0044] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0045] Combination Figure 1 A cavity-pillar bonded shape memory polymer stamp includes a substrate, a cavity-pillar bonded unit 2, a polyimide substrate layer 3, and a transparent quartz substrate 4.

[0046] The cavity-column bonding unit 2 is made of shape memory polymer and is disposed on one side of the substrate. In this embodiment, the substrate is shape memory polymer substrate 1, and the cavity-column bonding unit 2 is made on the basis of shape memory polymer substrate 1, naturally forming the structure of substrate and cavity-column bonding unit 2.

[0047] On the other side of the substrate, a polyimide substrate layer 3 and a transparent quartz substrate 4 are sequentially disposed;

[0048] A carbon layer is disposed on the surface of the polyimide substrate layer 3 to increase the absorption of 808nm infrared laser.

[0049] The cavity column bonding unit 2 is used to adsorb the workpiece to be transferred, and the polyimide substrate layer 3 and the transparent quartz substrate 4 work together with the laser to achieve temperature regulation of the stamp.

[0050] The cavity-column bonding unit 2 includes a uniformly arranged array of micropillars, each of which is independently positioned within a uniformly arranged cavity; the height of the micropillars is greater than the depth of the cavity. In this embodiment, the cavity depth of the cavity-column bonding unit 2 is adapted to the height of the micropillars, the diameter of the micropillars is 70μm~100μm, and the gap between the cavity and the micropillars is 50μm~100μm. Its elastic modulus is ≥1.7GPa when the temperature is below the glass transition temperature, making it resistant to deformation; and its elastic modulus is ≤1MPa when the temperature is above the glass transition temperature, making it easily deformable and able to withstand ≥75% tensile strain.

[0051] In this embodiment, the shape memory polymer is a shape memory epoxy resin, which is composed of epoxy resin E44 and curing agent D230 in a certain mass ratio, for example, 1:0.35 to 1:0.55.

[0052] Combination Figure 2 The preparation process of the polyimide substrate 3 includes:

[0053] After a non-photosensitive polyimide precursor solution was spin-coated onto a transparent quartz substrate 4 for a certain period of time, the substrate was heated on a hot plate. After spin-coating and curing multiple layers, the substrate was heated at 220°C for 4 hours to prepare a 15μm thick polyimide film 3.1.

[0054] The energy utilized is 222 mJ / cm 2 A 308nm excimer laser irradiates a polyimide film 3.1 through a transparent quartz substrate 4 1000 times. The polyimide film 3.1 irradiated by the excimer laser absorbs the laser energy and undergoes carbonization to form a carbonized layer 3.2 to enhance the absorption of infrared laser. After 12 hours of rest, the internal gas escapes and the polyimide film 3.1 flattens out.

[0055] The fabrication process of the cavity column bonding unit 2 includes:

[0056] Preparation of shape memory polymer substrate 1:

[0057] After mixing epoxy resin E44 and curing agent D230 at a mass ratio of 1:0.35~1:0.65, vacuum evacuation is performed. The mixture solution is poured into PDMS film mold 5 and sealed with polyimide substrate 3 with carbon layer and transparent quartz substrate 4. Then it is cured at 90°C on a hot plate and then demolded to complete the preparation of shape memory polymer substrate.

[0058] The mixing ratio of epoxy resin E44 to curing agent D230 directly affects the glass transition temperature of the shape memory polymer. The glass transition temperature varies with the mass ratio of epoxy resin E44 to curing agent D230. The higher the content of curing agent D230, the lower the glass transition temperature. When the mass ratio of epoxy resin E44 to curing agent D230 varies in the range of 1:0.35 to 1:0.55, the glass transition temperature changes from 75°C to 45°C.

[0059] Combination Figure 3 Micropillar arrays and cavities of cavity-pillar bonding unit 2 were fabricated on a shape memory polymer substrate:

[0060] A 355nm ultraviolet picosecond laser 6 was used to selectively cut the surface of the shape memory polymer substrate 1. The laser scanning path for cutting the micropillars and cavities adopted a horizontal and vertical path, and the cutting was divided into two parts. In the first cutting, a micropillar array was cut out. Using preset laser parameters (laser power set to 12%, number of cuts to 20), a layer was removed from the surface of the shape memory polymer substrate 1 except for the reserved micropillar array positions, forming a micropillar array with a certain height on the surface of the shape memory polymer substrate 1. In the second cutting, a cavity was cut out. According to preset laser parameters (laser power set to 20%, number of cuts to 20), the cavity was cut at the annular position at the edge of the micropillars, and finally a cavity-pillar combined unit 2 with a micropillar height higher than the cavity edge was formed, and the stamp preparation was completed.

[0061] The laser scanning path adopts a horizontal and vertical path. If a circular scanning path is adopted, the cavity-column bonding unit 2 will be uneven due to the small spacing of the circular path and the small radius of the micropillar. Using a horizontal and vertical path for scanning can effectively improve the surface morphology of the cut cavity-column bonding unit 2.

[0062] Combination Figure 4 This solution also provides a microchip proximity transfer method using the above-mentioned cavity-pillar combined shape memory polymer stamp, including the following steps:

[0063] (1) Pick-up phase:

[0064] Align one side of the cavity column bonding unit 2 of the cavity column bonding type shape memory polymer stamp with the target chip 7 on the donor substrate 8, and apply a certain pre-pressure 10 (e.g., 10-40N) to make the cavity column bonding unit 2 and the surface of the target chip 7 fit tightly together.

[0065] In addition, during the pickup stage, the adhesion strength between the cavity column bonding unit 2 of the stamp and the target chip is affected by the pre-pressure. The more pre-pressure is applied, the higher the adhesion strength.

[0066] Maintaining pre-pressure, the hot plate 9 is used to heat the cavity-pillar bonding unit 2 to a temperature greater than the glass transition temperature. At this time, the elastic modulus of the cavity-pillar bonding shape memory polymer stamp decreases, and it deforms under pressure. The micropillar contacts the target chip 7 and is compressed into the cavity by the target chip 7. The contact area between the cavity-pillar bonding shape memory polymer stamp and the target chip 7 increases, and the adhesion strength is enhanced. Then, cooling is performed to lower the stamp temperature below the glass transition temperature and shape it. At this time, the cavity-pillar bonding shape memory polymer stamp and the target chip 7 still maintain a high contact area and high adhesion strength. At the same time, the cavity generates negative pressure after the heating and cooling process, which further enhances the adhesion strength to the target chip. The target chip 7 leaves the donor substrate 8. At this time, the pickup adhesion strength is greater than 20 kPa.

[0067] (2) Transfer phase:

[0068] While maintaining the picking state, move the stamp with the target chip 7 adsorbed to the top of the acceptor substrate 12, and adjust the gap between the stamp and the acceptor substrate 12 to a preset distance.

[0069] (3) Release phase:

[0070] An 808nm infrared laser 11 is used to irradiate the cavity-pillar bonded shape memory polymer stamp from one side of the transparent quartz substrate 4. The carbon layer of the polyimide substrate 3 absorbs the 808nm infrared laser 11, thereby generating heat. The heat is transferred to the cavity-pillar bonded unit 2, raising its temperature above the glass transition temperature. The cavity-pillar bonded unit 2 of the cavity-pillar bonded shape memory polymer stamp returns to its original shape, the contact area with the target chip 7 decreases, the negative pressure disappears, and the residual adhesion strength is less than 0.1kPa. At the same time, the micropillars return to their original height. Under the action of the directional push generated when the micropillars return to their original height and their own gravity, the target chip 7 adheres to the recipient substrate 12, completing the proximity transfer.

[0071] It should be noted that the surface roughness of the target chip is 1nm~500nm, and the material includes any one of silicon, polyimide, copper, glass or acrylic; and the higher the roughness of the target chip 7, the higher the adhesion strength to the stamp under the same pre-pressure.

[0072] The adhesion strength test method is to use a material tensile testing machine, fix the stamp, use a clamp to hold the target chip, and control the clamp to move upward at a fixed speed. The faster the movement speed, the higher the measured adhesion strength.

[0073] The maximum strain of the cavity-column combined shape memory polymer stamp during the picking process should be ≤0.27 to avoid damage to the stamp structure.

[0074] This invention presents a cavity-pillar combined shape memory polymer stamp using shape memory epoxy resin as the matrix. The cavity-pillar combined structure is directly formed through laser micromachining. Utilizing the change in elastic modulus before and after the glass transition temperature, an adhesion switching ratio as high as 1200 is achieved. Combined with negative pressure-assisted adsorption and micropillar directional pushing, this enables high-adhesion pickup, low-adhesion release, and high-precision proximity transfer of microchips at low cost. The stamp fabrication process of this invention is simple, requiring no complex photolithography. The fabrication parameters can be flexibly adjusted according to the performance requirements of the stamp, solving the problems of complex fabrication, narrow applicability, and low transfer reliability of existing transfer technologies.

[0075] The embodiments described above are merely one implementation method of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A cavity-column combined shape memory polymer stamp, characterized in that, It includes a substrate, a cavity pillar bonding unit (2), a polyimide substrate layer (3), and a transparent quartz substrate (4). The cavity column bonding unit (2) is made of shape memory polymer and is disposed on one side of the substrate; On the other side of the substrate, a polyimide substrate layer (3) and a transparent quartz substrate (4) are disposed in sequence. A carbon layer is disposed on the surface of the polyimide substrate layer (3); The cavity column unit (2) is used to adsorb the workpiece to be transferred, and the polyimide substrate (3) and the transparent quartz substrate (4) work together with the laser to adjust the temperature of the stamp.

2. The cavity-column combined shape memory polymer stamp according to claim 1, characterized in that, The cavity-column combination unit (2) includes a uniformly arranged array of micropillars, and each micropillar in the array is independently arranged in a uniformly arranged cavity. The height of the micropillar is greater than the depth of the cavity.

3. The cavity-column combined shape memory polymer stamp according to claim 1, characterized in that, The shape memory polymer is a shape memory epoxy resin, which is composed of epoxy resin and curing agent in a certain mass ratio.

4. The cavity-column combined shape memory polymer stamp according to claim 2, characterized in that, The preparation process of the cavity column bonding unit (2) includes: Preparation of shape memory polymer substrates: After mixing epoxy resin E44 and curing agent D230 at a mass ratio of 1:0.35~1:0.65, vacuum evacuation was performed. The mixture solution was poured into the PDMS mold and sealed with the polyimide substrate (3) with carbon layer and the transparent quartz substrate (4). Then it was cured at 90°C on a hot plate and then demolded to complete the preparation of the shape memory polymer substrate. Micropillar arrays and cavities of cavity-pillar bonded units (2) are fabricated on shape memory polymer substrates: The surface of the shape memory polymer substrate was selectively cut using a 355nm ultraviolet picosecond laser. The cutting was performed in two steps. In the first step, a micropillar array was cut out. Using preset laser parameters, a layer was removed from the entire surface of the shape memory polymer substrate except for the reserved micropillar array positions, forming a micropillar array with a certain height on the surface of the shape memory polymer substrate. In the second step, a cavity was cut out. According to preset laser parameters, the cavity was cut at the annular position at the edge of the micropillars, and finally a cavity-pillar combined unit (2) with the height of the micropillars higher than the edge of the cavity was formed, and the stamp preparation was completed.

5. The cavity-column combined shape memory polymer stamp according to claim 4, characterized in that, The laser scanning path adopts a horizontal and vertical path.

6. The cavity-column combined shape memory polymer stamp according to claim 2, characterized in that, The preparation process of the polyimide substrate layer (3) includes: After a certain time, a non-photosensitive polyimide precursor solution was spin-coated onto a transparent quartz substrate (4), and then heated on a hot plate. After spin-coating and curing multiple layers, a 15 μm thick polyimide film was prepared by heating at 220°C for 4 hours (3.1). The energy utilized is 222 mJ / cm 2 A 308nm excimer laser irradiates a polyimide film (3.1) through a transparent quartz substrate (4) 1000 times. The polyimide film (3.1) irradiated by the excimer laser absorbs the laser energy and carbonizes to form a carbonized layer (3.2) to enhance the absorption of infrared laser. After 12 hours of rest, the internal gas overflows and the polyimide film (3.1) flattens out.

7. The microchip proximity transfer method for cavity-pillar combined shape memory polymer stamps according to any one of claims 1-6, characterized in that, Includes the following steps: (1) Pick-up phase: Align one side of the cavity-pillar bonding unit (2) of the cavity-pillar bonding type shape memory polymer stamp with the target chip on the donor substrate, apply a certain pre-pressure, and make the cavity-pillar bonding unit (2) fit tightly against the surface of the target chip. Maintaining pre-pressure, heating makes the temperature of the cavity-pillar bonding unit (2) greater than the glass transition temperature. At this time, the elastic modulus of the cavity-pillar bonding shape memory polymer stamp decreases and deforms under pressure. The micropillar contacts the target chip and is squeezed by the target chip, shortening into the cavity. The contact area between the cavity-pillar bonding shape memory polymer stamp and the target chip increases, and the adhesion strength is enhanced. Then, cooling is performed to make the stamp temperature lower than the glass transition temperature and shape it. At this time, the cavity-pillar bonding shape memory polymer stamp and the target chip still maintain a high contact area and high adhesion strength. At the same time, the cavity generates negative pressure after the heating and cooling process, which further enhances the adhesion strength to the target chip. The target chip leaves the donor substrate. At this time, the pick-up adhesion strength is greater than 20 kPa. (2) Transfer phase: While maintaining the picking state, move the stamp with the target chip attached to it above the recipient substrate and adjust the gap between the stamp and the recipient substrate to a preset distance. (3) Release phase: An infrared laser (11) with a wavelength of 808 nm is used to irradiate the cavity-pillar bonded shape memory polymer stamp from one side of the transparent quartz substrate (4). The carbon layer of the polyimide substrate (3) absorbs the 808 nm infrared laser (11) to generate heat. The heat is transferred to the cavity-pillar bonded unit (2) to raise its temperature above the glass transition temperature. The cavity-pillar bonded unit (2) of the cavity-pillar bonded shape memory polymer stamp returns to its original state, the contact area with the target chip is reduced, the negative pressure disappears, and the residual adhesion strength is less than 0.1 kPa. At the same time, the micropillars return to their original height. Under the action of the directional push generated when the micropillars return to their original height and their own gravity, the target chip adheres to the recipient substrate, completing the proximity transfer.

8. The microchip proximity transfer method according to claim 7, characterized in that, The picking stage affects the adhesion strength between the cavity column bonding unit (2) of the stamp and the target chip through pre-pressure. The more pre-pressure applied, the higher the adhesion strength. The higher the heating temperature during the pickup stage, the higher the adhesion strength.

9. The microchip proximity transfer method according to claim 7, characterized in that, The surface roughness of the target chip is 1nm~500nm, and the material includes any one of silicon, polyimide, copper, glass or acrylic. The higher the roughness of the target chip (7), the stronger its adhesion to the stamp under the same pre-pressure.

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