Intelligent microstructure seal for large-area micro transfer printing and micro transfer printing method thereof

Abstract

A main body of the seal is made of a viscous-elastic material, the seal is provided with a base body and a plurality of seal units of the same structure, the seal units are arranged below the base body in a rectangular array mode, the seal units are provided with columns connected with the base body, and the columns are connected with the base body. A protruding microstructure is arranged in the middle of the bottom face of the column body, a sensing device is arranged behind the column body, and the sensing device is embedded in the base body. The invention further discloses a micro transfer printing method adopting the seal. The magnitude of force can be monitored in real time through the sensing device; by means of the collapse characteristic of the microstructure, strong and weak bonding states can be rapidly switched, the adhesive force can be greatly changed, and the method has the advantages of being high in yield, high in reliability and high in repeatability and is not affected by the property of a target substrate material in the release stage. And meanwhile, the seal can realize large-area micro transfer printing.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of micro transfer printing, and particularly relates to an intelligent micro structure stamp for large-area micro transfer printing. BACKGROUND

[0002] In recent years, with the vigorous development of biology, energy, electronic information, material science and high-end manufacturing equipment, the related industries have higher and higher requirements for the manufacturing technology of micro / nano electronic devices. Although the development of micro / nano manufacturing technology presents a diversified trend, and derives micro / nano manufacturing technologies such as photolithography, soft lithography, nano-imprint, 3D micro-printing, etc., there are problems such as low manufacturing efficiency, high requirement for working environment, and high cost. The deterministic micro transfer printing technology can effectively avoid the pollution of chemical solution to the flexible substrate and the restriction of high temperature in the processing process, and can accurately obtain large-area micro / nano flexible electronic devices, and has great application potential in the field of multi-layer heterogeneous integration manufacturing of large-area flexible micro / nano devices. The basic working process of micro transfer printing includes two stages of extraction and release. In the extraction stage, the micro / nano device is peeled off from the source substrate by using the stamp; in the printing stage, the micro / nano device is released to the target substrate. The yield of micro transfer printing depends on the adhesion effect of the stamp and the micro / nano device and the micro / nano device and the substrate. In order to successfully complete the micro transfer printing, it is necessary to ensure that the micro / nano device and the source substrate are easily separated in the extraction stage, and the micro / nano device and the stamp are easily separated in the printing stage.

[0003] With the evolution of micro transfer printing technology towards high precision and high reliability, the micro transfer printing technology system has developed various technical methods, including speed control micro transfer printing, load assisted micro transfer printing, laser driven micro transfer printing, and adhesive tape assisted micro transfer printing. Compared with other micro transfer printing methods, the performance of micro structure assisted micro transfer printing is stable, and the adhesion force can be stably controlled, which is the main direction of future micro transfer printing technology research. However, there are still some problems in the research of micro structure stamp, such as relatively complicated adhesion force control process of the stamp, complex structure of the stamp, and inability of the stamp to realize real-time monitoring of force signal. Therefore, research needs to be carried out on the design of high-performance micro structure stamp, and a micro structure stamp capable of realizing real-time monitoring of force signal and large-area micro transfer printing is invented. SUMMARY

[0004] The application provides an intelligent micro structure stamp for large-area micro transfer printing and a micro transfer printing method thereof, which can realize real-time monitoring of force signal and large-area micro transfer printing.

[0005] The technical scheme adopted by the present application to solve the technical problems in the prior art is: an intelligent microstructure stamp for large-area micro transfer, the main body of the stamp is made of viscoelastic material, and is provided with a base and a plurality of stamp units with the same structure, the stamp units are arranged in a rectangular array form under the base, the stamp units are provided with a column connected with the base, a protruding microstructure is arranged in the center of the bottom surface of the column, and a sensor device is arranged at the rear of the column, and the sensor device is embedded in the base.

[0006] On the basis of the above scheme, the present application further makes the following improvements:

[0007] The base, the column and the microstructure adopt an integrated molding structure.

[0008] The main body of the stamp is made of organic silicon.

[0009] The cross-sectional circumscribed circle radius of the microstructure is smaller than the cross-sectional circumscribed circle radius of the column.

[0010] The shape of the microstructure is petal-shaped or star-shaped.

[0011] The sensor device adopts a rectangular thin film structure.

[0012] The material of the sensor device adopts piezoelectric material or piezoresistive material.

[0013] The base is in a flat plate structure, and the cross-sectional shape is circular or rectangular.

[0014] The column is a cylindrical column or a square column.

[0015] Another technical scheme adopted by the present application to solve the technical problems in the prior art is: a micro transfer method using the above stamp, and the following steps are adopted:

[0016] 1) Before extraction, three industrial cameras I are arranged orthogonally above, in front of and on one side of the micro-nano device on the source substrate, and the field intersection points of the three industrial cameras I are aligned with the micro-nano device; 2) During extraction, based on the real-time visual feedback of the three industrial cameras I, the mechanical system drives the stamp to move horizontally above the micro-nano device, and then moves downward until the stamp is in contact with the micro-nano device. During this process, the relative position is determined based on the image detection of the industrial camera I, and the contact between the stamp and the micro-nano device is confirmed based on the contact force signal detected by the sensor. After confirming that the stamp is in contact with the micro-nano device, pressure is applied to the top of the stamp base. During this process, the microstructure is confirmed to be pressed into the column and the column bottom surface is in close contact with the micro-nano device based on the real-time image detection of the industrial camera I. Finally, the adhesion is confirmed based on the microstructure collapse pressure signal detected by the sensor. At this time, the interfacial adhesion between the micro-nano device and the stamp unit is greater than the binding force between the micro-nano device and the source substrate. The mechanical system drives the stamp to move upward, and the micro-nano device is extracted from the source substrate by using the adhesion of the stamp; 3) Before printing, three industrial cameras II are arranged orthogonally above, in front of and on one side of the target position of the target substrate, and the field intersection points of the three industrial cameras II are aligned with the target position; 4) During release, based on the real-time visual feedback of the three industrial cameras II, the mechanical system drives the stamp to move horizontally to the target position, and then moves the micro-nano device downward until it is in contact with the target substrate. During this process, the relative position is determined based on the image detection of the industrial camera II, and the contact between the micro-nano device and the target substrate is confirmed based on the contact force signal detected by the sensor. After standing, wait for the microstructure to rebound. The microstructure is confirmed to pop up based on the image detection of the industrial camera II, and the micro-nano device is pushed down to separate it from the column bottom surface. Based on the fact that the sensor cannot detect the pressure signal, it is confirmed that the micro-nano device has successfully escaped from the adhesion state. At this time, the interfacial adhesion between the micro-nano device and the stamp unit is less than the binding force between the micro-nano device and the target substrate. The mechanical system drives the stamp to move upward, and the micro-nano device is printed on the target substrate; 5) Start the next cycle. After the micro-nano device is printed, the mechanical system drives the stamp to move horizontally to a new batch of micro-nano devices under the assistance of the industrial camera II, and repeats the above steps until all the micro-nano devices are printed.

[0017] The application has the advantages and positive effects that in the stamp extraction stage, the microstructure is pressed and is in a "collapse" state, the lower surface of the column contacts the micro-nano device, the adhesion area is about the cross-sectional area of the column, and the state is strong adhesion; in the stamp release stage, the microstructure rebounds and is out of the "collapse" state, the lower surface of the column is separated from the micro-nano device, the adhesion area is about the cross-sectional area of the microstructure, and the state is weak adhesion. The application adjusts the adhesion force between the stamp and the micro-nano device by using the "collapse" characteristics of the microstructure, can quickly switch the strong and weak adhesion states, greatly changes the adhesion force, has the characteristics of high yield, strong reliability and strong repeatability, and is not affected by the properties of the target substrate material in the release stage. And the base body, the column and the microstructure adopt an integrated structure, so that the whole stamp has the characteristics of compact structure, small volume, light weight and convenient control, and the high precision of the stamp transfer printing can be effectively ensured. The sensor device deforms with the extraction and release of the stamp, and the force can be monitored in real time. The column and the microstructure are arrayed on the base body to form an arrayed intelligent micro transfer stamp, a plurality of micro-nano devices can be extracted at one time, large-area micro transfer can be realized, and the application has great application prospect in the field of large-area micro-nano manufacturing.

[0018] In summary, the application can greatly adjust the adhesion force by using the "collapse" characteristics of the microstructure, and controllably realize the extraction and release of the micro-nano device. Meanwhile, the stamp can realize large-area micro transfer. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is an isometric view of the stamp according to the application;

[0020] Figure 2 It is an isometric view of the stamp unit according to the application;

[0021] Figure 3 It is a sectional view of the stamp unit according to the application;

[0022] Figure 4 It is a shape diagram of various microstructures used in the application;

[0023] Figure 5 It is a micro transfer operation flowchart used in the application;

[0024] Figure 6 It is a schematic diagram of the stamp unit according to the application before "collapse" deformation;

[0025] Figure 7 It is a schematic diagram of the stamp unit according to the application after "collapse" deformation.

[0026] Legend: 1-base body; 2-column; 3-microstructure; 4-sensor device; 5-micro-nano device. DETAILED DESCRIPTION

[0027] In order to further understand the inventive content, features and effects of the present application, the following examples are given in detail below with reference to the accompanying drawings.

[0028] Please refer to Figures 1-7 The intelligent microstructure stamp for large-area micro transfer is made of viscoelastic material, and is provided with a base body 1 and a plurality of stamp units with the same structure, which are arranged in a rectangular array under the base body 1. The stamp unit is provided with a column 2 connected with the base body 1, and a protruding microstructure 3 is arranged in the center of the bottom surface of the column 2. A sensor device 4 is arranged at the rear of the column 2, and is embedded in the base body 1.

[0029] The more preferred scheme of the above stamp is as follows:

[0030] The base body 1, the column 2 and the microstructure 3 are integrally formed, which is stable in structure and good in performance.

[0031] The main body of the stamp is made of organic silicon, but is not limited to organic silicon.

[0032] The cross-sectional circumscribed circle radius of the microstructure 3 is smaller than that of the column 2, which is good in reliability.

[0033] The shape of the microstructure 3 is recommended to be petal-shaped or star-shaped, but is not limited to petal-shaped and star-shaped.

[0034] The sensor device 4 is recommended to adopt a rectangular thin film structure, but is not limited to a rectangular thin film structure.

[0035] The material of the sensor device 5 is recommended to adopt piezoelectric material or piezoresistive material, but is not limited to piezoelectric material or piezoresistive material.

[0036] The base body 1 is in a flat plate structure, and the cross-sectional shape is recommended to be circular or rectangular, but is not limited to circular and rectangular.

[0037] The column 2 is a cylindrical column or a square column, but is not limited to a cylindrical column and a square column.

[0038] The micro transfer method using the above stamp adopts the following steps:

[0039] 1) Before extraction, three industrial cameras I are arranged orthogonally above, in front of and on one side of the micro-nano device on the source substrate, and the field of view intersection points of the three industrial cameras I are aligned with the micro-nano device.

[0040] 2) Extraction stage, based on the real-time visual feedback of the three industrial cameras I, the mechanical system drives the stamp to move horizontally above the micro-nano device, and then moves downward until the stamp contacts the micro-nano device. During this process, the relative position is judged based on the image detection of the industrial camera I, and finally the contact force signal is detected by the sensor 4 to confirm that the stamp contacts the micro-nano device 5 successfully. Based on the contact force signal detected by the sensor, it is confirmed that the stamp contacts the micro-nano device successfully. After confirming that the stamp contacts the micro-nano device successfully, pressure is applied to the top of the stamp base. During this process, the real-time image detection based on the industrial camera I confirms that the microstructure is pressed into the column body, and it is confirmed that the surface of the microstructure 3 collapses. At the same time, the lower surface of the column 2 is in close contact with the micro-nano device 5, greatly increasing the effective contact area between the stamp and the micro-nano device 5, thereby causing the interfacial adhesion to be significantly enhanced. The schematic diagram of the stamp unit before and after deformation is shown in Figure 6 and Figure 7 . Finally, the pressure signal is detected by the sensor 4 and it is confirmed that the adhesion is successful. At this time, the interfacial adhesion between the micro-nano device 5 and the stamp is greater than its binding force with the source substrate, and the mechanical system drives the stamp to move upward quickly, and the adhesion force of the stamp is used to extract the micro-nano device 5 from the source substrate.

[0041] 3) Before printing, three industrial cameras II are arranged orthogonally above, in front of and on one side of the target position of the target substrate, and the field of view intersection point of the three industrial cameras II is aligned with the target position.

[0042] 4) Release stage, based on the real-time visual feedback of the three industrial cameras II, the mechanical system drives the stamp to move horizontally to the target position, and then moves the micro-nano device downward until it contacts the target substrate. During this process, the relative position is judged based on the image detection of the industrial camera II, and finally the contact force signal detected by the sensor is used to confirm that the micro-nano device contacts the target substrate successfully.

[0043] Rest, wait for the microstructure to rebound.

[0044] Release, based on the image detection of the industrial camera II, it is confirmed that the microstructure pops out, and the micro-nano device 5 is pushed downward to separate it from the bottom surface of the column 2. At this time, the effective contact area between the stamp and the micro-nano device 5 is greatly reduced, thereby causing the interfacial adhesion to be significantly reduced. The sensor 4 cannot detect the pressure signal, confirming that the micro-nano device 5 successfully escapes from the adhesion state. At this time, the interfacial adhesion between the micro-nano device 5 and the stamp unit is less than its binding force with the target substrate, and the mechanical system drives the stamp to move slowly upward, and the micro-nano device 5 is successfully printed on the target substrate.

[0045] 5) Start the next cycle, after the micro-nano device 5 is printed, under the assistance of the industrial camera II, the mechanical system drives the stamp to move horizontally to a new batch of micro-nano devices, and repeats the above steps until all the micro-nano devices are printed.

[0046] Although the preferred embodiments of the present application have been described above with reference to the accompanying drawings, the present application is not limited to the above-described specific embodiments, and the above-described specific embodiments are merely illustrative and are not restrictive, and a person of ordinary skill in the art can make many forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims, and these all belong to the protection scope of the present application.

Claims

1. A smart microstructure stamp for large-area micro-transfer printing, characterized in that, The main body of the stamp is made of viscoelastic material and has a base and multiple stamp units with the same structure. The stamp units are arranged in a rectangular array under the base. Each stamp unit has a column connected to the base. A protruding microstructure is provided in the center of the bottom surface of the column. A sensor is provided behind the column and is embedded in the base.

2. The intelligent microstructure stamp for large-area micro-transfer printing according to claim 1, characterized in that, The substrate, the column, and the microstructure are integrally molded.

3. The intelligent microstructure stamp for large-area micro-transfer printing according to claim 1, characterized in that, The main body of the seal is made of silicone.

4. The intelligent microstructure stamp for large-area micro-transfer printing according to claim 1, characterized in that, The radius of the circumcircle of the cross-section of the microstructure is smaller than the radius of the circumcircle of the cross-section of the cylinder.

5. The intelligent microstructure stamp for large-area micro-transfer printing according to claim 1, characterized in that, The microstructure is petal-shaped or star-shaped.

6. The intelligent microstructure stamp for large-area micro-transfer printing according to claim 1, characterized in that, The sensor device adopts a rectangular thin film structure.

7. The intelligent microstructure stamp for large-area micro-transfer printing according to claim 1, characterized in that, The sensor is made of piezoelectric or piezoresistive material.

8. The intelligent microstructure stamp for large-area micro-transfer printing according to claim 1, characterized in that, The substrate has a flat plate structure with a circular or rectangular cross-section.

9. The intelligent microstructure stamp for large-area micro-transfer printing according to claim 1, characterized in that, The column can be a cylindrical or square column.

10. A method for micro-transfer printing using the seal as described in claim 1, characterized in that, The following steps are adopted: 1) Before extraction, three industrial cameras I are orthogonally arranged on the source substrate directly above, in front of and to one side of the micro / nano device, and the intersection of the fields of view of the three industrial cameras I is aligned with the micro / nano device. 2) During the extraction stage, based on the real-time visual feedback from the three industrial cameras I, the mechanical system moves the stamp horizontally above the micro / nano device and then downwards until the stamp contacts the micro / nano device. During this process, the relative position is determined by image detection from the industrial cameras I, and the contact force signal detected by the sensors confirms successful contact between the stamp and the micro / nano device. After confirming successful contact between the stamp and the micro / nano device, pressure is applied to the top of the stamp substrate. During this process, real-time image detection from the industrial cameras I confirms that the microstructure is pressed into the column and that the bottom surface of the column is in close contact with the micro / nano device. Finally, the adhesion is confirmed by the collapse pressure signal of the microstructure detected by the sensors. At this point, the interfacial adhesion force between the micro / nano device and the stamp unit is greater than its bonding force with the source substrate. The mechanical system moves the stamp upwards and uses the adhesion force of the stamp to extract the micro / nano device from the source substrate. 3) Before printing, three industrial cameras II are orthogonally arranged above, in front of and to one side of the target position on the target substrate, with the intersection of the fields of view of the three industrial cameras II aligned with the target position. 4) During the release phase, based on the real-time visual feedback from three industrial cameras II, the mechanical system moves the stamp horizontally to the target position and lowers the micro-nano device until it contacts the target substrate. During this process, the relative position is determined by image detection from the industrial cameras II, and finally the contact force signal detected by the sensor device confirms that the micro-nano device has successfully contacted the target substrate. Let it stand still and wait for the microstructure to spring back; Based on the image detection of the industrial camera II, the microstructure pops out and pushes the micro-nano device down to separate it from the bottom of the column. Since the sensor cannot detect the pressure signal, it is confirmed that the micro-nano device has successfully detached from the adhesive state. At this time, the interfacial adhesion force between the micro-nano device and the stamp unit is less than the bonding force between the micro-nano device and the target substrate. The mechanical system drives the stamp to move upward and print the micro-nano device on the target substrate. 5) Start the next cycle. After the micro-nano devices are printed, with the assistance of industrial camera II, the mechanical system moves the stamp horizontally to a new batch of micro-nano devices and repeats the above steps until all micro-nano devices are printed.

Images