CN112477391B

CN112477391B - Magnetic control transfer printing stamp based on bistable structure and transfer printing method

Info

Publication number: CN112477391B
Application number: CN202011356638.0A
Authority: CN
Inventors: 李城隆; 罗鸿羽; 宋吉舟
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2020-11-27
Filing date: 2020-11-27
Publication date: 2022-05-10
Anticipated expiration: 2040-11-27
Also published as: CN112477391A

Abstract

The invention discloses a magnetic control transfer printing stamp based on a bistable structure and a transfer printing method, wherein the stamp is of a two-dimensional structure and comprises a stamp main body with a cavity array, a bistable structure magnetic film and an adhesion block arranged at the bottom of the bistable structure magnetic film; the transfer printing method comprises the following steps: 1) when picking up, the seal is pressed on the element/substrate, and the element is picked up from the donor substrate by using the viscosity of the seal/element interface; 2) during printing, under the continuous action of an external magnetic field, the bistable structure magnetic film on the stamp deforms and jumps downwards to generate impact force and deformation extrusion force on the element, so that the element is separated from the stamp and is printed on a receiver substrate. The seal has simple structure and low cost; the response speed is high; non-contact transfer printing can be realized at normal temperature and in a vacuum environment; has stronger pick-up and printing performance; the method can realize high-efficiency global transfer printing and accurate patterning transfer printing by changing the action range of the magnetic field.

Description

Magnetic control transfer printing stamp based on bistable structure and transfer printing method

Technical Field

The invention relates to a transfer printing technology, in particular to a magnetic control transfer printing stamp based on a bistable structure and a transfer printing method, which can be used for transfer printing of electronic components with any patterns.

Background

The transfer technique is a multifunctional material assembly technique that transfers a large number of discretely prepared electronic components from a conventional rigid substrate (donor substrate) to another non-conventional (e.g., flexible or stretchable) receiving substrate (recipient substrate) through a flexible polymer stamp, thereby assembling into two-or three-dimensionally ordered integrated arrays (see, for example, rochon, army, songba. research on transfer mechanics of ductile flexible inorganic electronic devices, review [ J ] china science: physics mechanics astronomy, 2018, v.48(09): 134-. The polymer stamp is convenient to manufacture, low in cost, high in transfer efficiency and wide in range of transferable materials, so that the polymer stamp is often used for integration and preparation of various electronic devices. Such as thin-film solar cells (thin-film solar cells), flexible capacitors (flexible capacitors), Light Emitting Diodes (LEDs), flexible electrodes, flexible display screens, etc., are assembled by a transfer printing technique.

Generally, the process of the transfer technique is divided into two steps of pickup and printing. Picking up an element from a donor substrate requires that the seal/element interface have a stronger adhesion than the element/substrate, and printing the element onto a receiver substrate requires that the seal/element interface have a weaker adhesion than the element/substrate. Therefore, regulating the interfacial adhesion of the stamp/component is critical to achieving transfer pick-up and printing.

Prior transfer techniques, such as ratio-dependent transfer techniques (Meitl M, Zhu Z, Kumar V, et al. transfer printing by kinetic control of additive to an elastomeric stamp [ J ]. Nature Materials,2006,5(1):33-38.), surface relief transfer techniques (Kim S, Wu J, Carlson A, et al. microscopic transfer printing with kinetic additive addition and extraction of the same use in a shear enhancing transfer [ J ]. processing of the same National additive of science 2010,107(40): 95-17100.), shear enhancing transfer techniques (Kim-Z, Kumar V, et al. transfer printing by kinetic control of additive [ J ]. transfer printing of the same natural additive of science [ 2010,107, 40): 95-17100 ], shear enhancing transfer techniques (Heat-transfer J, laser of shear processing J., 2011. transfer printing of the same kind [ Li-1J ]. transfer printing J.: Wideal J., thermal transfer printing of the same, U.2011-additive [ Li-1 J.: 1-1. transfer printing of the same J.: laser of transfer printing of the same kind of transfer printing, U. Soft Matter,2012,8(27):7122-7127.) and area modulated transfer techniques (Carlson A, Wang S, Elvikis P, et al active, programmable elastomeric surfaces with a structured addition for a defined application by transfer printing [ J ]. Advanced Functional Materials,2012,22(21):4476-4484.) are all transferred by adjusting the interfacial adhesion between the stamp and the element.

However, in these methods, the interface adhesion between the stamp and the element is reduced by reducing the interface adhesion strength, which is affected by the material parameters, the separation speed, the pre-pressure, the contact area, and other factors, and the regulation range is limited, so that the element with strong interface adhesion of the stamp cannot be directly released, and the application range is limited.

Disclosure of Invention

The invention provides a magnetic control transfer printing stamp based on a bistable structure and a transfer printing method aiming at the defects of the prior transfer printing technology. This configuration provides greater release capability, enabling the stamp to release the element from a strongly adherent interface. The transfer-printing stamp is formed by sequentially assembling a stamp main body, a bistable-structure magnetic film and an adhesive block arranged at the bottom of the bistable-structure magnetic film from top to bottom, wherein the stamp is a two-dimensional stamp; the stamp main body is provided with a cavity array penetrating through the bottom of the stamp main body and used for providing a deformation space for the bistable structure magnetic thin film; the fixed end of the bistable structure magnetic film is fixed by the seal main body and the adhesion block.

The specific transfer printing method comprises the following steps: 1) when picking up, pressing the stamp on the surface of the element, and picking up the element by using the interface adhesion force between the adhesion block on the stamp and the element; 2) when printing, the stamp is moved to the position above the main substrate, a magnetic field is applied to the bistable magnetic film on the stamp to make the film deform and jump downwards, and impact force and deformation extrusion force are generated on the surface of an element to make the element overcome the interface adhesion force between the element and the stamp, so that non-contact printing is completed.

Besides the above picking mode, the magnetic film with the bistable structure which is popped out outwards can be used for applying deformation extrusion force to the surface of the element to counteract the adhesive force of the adhesive block on the stamp to the element, and the area without the counteracted adhesive force can pick up the element, so that the selective picking process is realized.

Besides the non-contact printing mode, a seal with an element can be pressed on the surface of a receiver substrate during printing, so that contact printing is realized, and the accuracy of a printing position and the printing success rate are improved.

In addition to the above printing method in which the magnetic field continuously acts, the magnetic thin film is deformed and jumped by momentary switching of the magnetic field during printing, and an impact force and a deformation pressing force are applied to the element to release the element. The fast switch of the magnetic field improves the safety of operation and reduces the energy consumption.

The external magnetic field can be global drive or local drive, and large-scale high-efficiency transfer printing is realized under the global drive; programmable patterned transfer is achieved under local drive.

The stamp main body can be made of non-magnetic materials with easy processing and higher modulus, such as polymer materials like PDMS (polydimethylsiloxane), non-magnetic metal materials or polymer materials like acrylic, the high modulus ensures that the stamp main body is not greatly deformed in the transfer process, and the non-magnetic ensures that the stamp main body is not influenced by a magnetic field.

The bistable structure magnetic film can be made of high-modulus ferromagnetic metal materials such as iron foil. The high modulus and the strong magnetism allow the film to apply large impact force and deformation extrusion force to the element, and the printing capacity of the stamp can be remarkably improved. Or a mixed material formed by high polymer and magnetic particles. The modulus of the bistable structure magnetic film is at least in the GPa grade, and the magnetic requirement is as follows: the bistable structure magnetic film can jump and turn under the action of magnetic force applied to the bistable structure magnetic film under the action of a magnetic field.

The adhesive block can be a single-layer or double-layer structure, such as a viscous polymer single-layer structure which is easy to prepare such as PDMS, SMP and the like, and a double-layer structure which is composed of a low-modulus substrate material and a viscous material such as adhesive tape and the like. The single-layer structure or the double-layer structure is used for ensuring that the stamp adhering block can have strong adhering and picking force on an element.

Preferably, to facilitate the preparation of the stamp, both the stamp body material and the stamp attachment block material may be selected to be PDMS (polydimethylsiloxane). The modulus of PDMS is adjusted by reasonably adjusting the proportion of the PDMS body and the curing agent, so that the deformation of the seal main body in the transfer process is reduced, and the adhesion force of an adhesion block during pickup is enhanced.

Preferably, to improve printing performance, the bistable magnetic thin film material can be selected as an iron foil.

The invention has the beneficial effects that: the seal has simple structure and low cost; the printing response time is fast, and the printing efficiency is high; the non-contact transfer printing can be realized at normal temperature or under vacuum; has stronger pick-up and printing performance; by changing the action range of the magnetic field, efficient global transfer printing can be realized, and accurate patterning transfer printing can also be realized.

Drawings

Fig. 1 is a schematic structural diagram of a minimum unit of a magnetic control transfer stamp based on a bistable structure.

FIG. 2 is a schematic diagram of a magnetic transfer stamp based on a bistable structure according to the present invention.

FIG. 3 is a flow chart of the contact printing of the magnetic control transfer stamp based on the bistable structure.

FIG. 4 is a flow chart of applying a transient magnetic field to a magnetic transfer stamp based on a bistable structure for printing according to the present invention.

FIG. 5 is a flow chart of applying a global magnetic field to a bistable structure-based magnetically controlled transfer stamp to achieve large-scale non-contact transfer according to the present invention.

FIG. 6 is a flow chart of the present invention for applying a local magnetic field to a bistable structure-based magnetically controlled transfer stamp to achieve programmable selective pickup.

FIG. 7 is a flow chart of programmable patterned non-contact printing by applying local magnetic field to a magnetic control transfer stamp based on a bistable structure according to the present invention.

In the figure: 1-stamp body 2-bistable structure magnetic film 3 without hopping deformation-bistable structure magnetic film 4 with hopping deformation-adhesive block 5-element 6-donor substrate 7-acceptor substrate 8-vertically downward magnetic field

Detailed Description

The invention is further described with reference to the following figures and examples.

As an example, but not limiting the scope of the present invention, fig. 1 is a schematic structural diagram of a minimum unit of the bistable structure-based magnetron transfer stamp of the present invention. The material of the seal main body 1 is PDMS (curing agent and body ratio is 1:10) prepared with a square cavity array; the bistable structure magnetic film is made of iron foil metal material; the material of the adhesion block 4 on the surface of the fixed end of the bistable structure magnetic film is PDMS with the ratio of curing agent to the body of 1: 10; these structures together make up the complete transfer stamp.

As an example, but not limiting the scope of the present invention, fig. 2 is a transfer schematic diagram of a bistable structure-based magnetically controlled transfer stamp proposed in the present invention. A-c in FIG. 2: the component is picked up using an adhesive mass. D-f in FIG. 2: in a continuously acting vertical downward magnetic field 8, the bistable structure magnetic film deforms and jumps, printing the element.

The stamp is first moved over the component 5 on the donor substrate 6 (fig. 2a), moved downwards to bring the adhesion block 4 into contact with the component 5 (fig. 2b), and the component 5 is peeled off from the donor substrate 6 by the adhesion of the adhesion block 4 (fig. 2c), thus completing the pick-up process.

Then, the stamp with the element 5 is transferred to the position above the receiver substrate 7, a space is kept between the stamp and the receiver substrate 7, a vertical downward magnetic field 8 (fig. 2d) is continuously applied, so that the bistable structure magnetic film 3 which generates deformation jumping due to magnetic force generates an impact force and deformation extrusion force on the element 5, the element 5 is printed on the receiver substrate 7 from the stamp (fig. 2e), and finally the stamp is removed, so that the non-contact printing process is realized (fig. 2 f).

As an example, but not limiting the scope of the present invention, fig. 3 is a flow chart of the contact printing of the bistable structure-based magnetically controlled transfer stamp proposed in the present invention. The stamp is first moved over the component 5 on the donor substrate 6 (fig. 3a), moved downwards to bring the adhesion block 4 into contact with the component (fig. 3b), and the component 5 is peeled from the donor substrate 6 by the adhesion of the adhesion block 4 (fig. 3c), thus achieving the pick-up process. Then, the stamp with the element 5 is transferred to the position above the receiver substrate 7, and is contacted with the receiver substrate 7, and a vertical downward magnetic field 8 (fig. 3d) is continuously applied, so that the bistable structure magnetic film 3 which generates deformation jumping due to the magnetic force generates an impact force and deformation extrusion force on the element 5, and the element 5 is printed on the receiver substrate 7 from the stamp (fig. 3e), and finally the stamp is removed, so that the contact printing process is realized (fig. 3 f).

As an example, but not limiting the scope of the present invention, fig. 4 is a flow chart of the present invention for printing by applying a transient magnetic field to a bistable structure-based magnetron transfer stamp. The stamp is first moved over the component 5 on the donor substrate 6 (fig. 4a), moved downwards to bring the adhesion block 4 into contact with the component 5 (fig. 4b), and the component 5 is peeled from the donor substrate 6 by the adhesion of the adhesion block 4 (fig. 4c), thus completing the pick-up process. Then, the stamp with the element 5 is transferred to the position above the receptor substrate 7 to contact the receptor substrate 7, and a vertically downward magnetic field 8 is applied and turned off in a short time (fig. 4d), so that the bistable structure magnetic thin film 3, which is deformed and jumped due to the magnetic force, generates an impact force and a deformation pressing force on the element 5, and the element 5 is printed on the receptor substrate 7 from the stamp (fig. 4e), and finally the stamp is removed, thereby realizing the contact printing process (fig. 4 f).

As an example, but not limiting the scope of the present invention, fig. 5 is a flow chart of applying a global magnetic field to a bistable structure-based magnetron transfer stamp to achieve large-scale non-contact transfer according to the present invention. The pick-up process (a-b in fig. 5) and the printing process (c-d in fig. 5) are the same as those of fig. 2, except that the whole transfer process uses a wide range of global magnetic fields to pick up and print the device in a large scale, thereby improving the transfer efficiency.

As an example, but not limiting the scope of the present invention, fig. 6 is a flow chart for programmable selective pickup by applying a local magnetic field to a bistable structure-based magnetically controlled transfer stamp. First, a vertically downward magnetic field 8 is applied to the bistable structure magnetic thin film 2 that is not deformed by jumping in a designated region of the stamp (fig. 6a), the bistable structure magnetic thin film 2 that is not deformed by jumping is deformed to jump, the non-adhesive state of the region is maintained (fig. 6b), and then the stamp is pressed against the element 5 placed on the donor substrate 6, and the bistable structure magnetic thin film 3 that is deformed by pressing against the element 5 is deformed (fig. 6 c); the stamp is then moved upwards, and the component 5 in the remaining position, except for the non-adhering area, is successfully selectively picked up (fig. 6 d).

As an example and not to limit the scope of the present invention, FIG. 7 is a flow chart for programmable patterned non-contact printing by applying a local magnetic field to a bistable structure-based magnetically controlled transfer stamp. The pick-up process is carried out by first pressing a stamp onto the element 5 on the donor substrate 6 (fig. 7a) and peeling the element 5 from the donor substrate 6 by the adhesive of the adhesive mass 4 (fig. 7 b). The stamp with the elements 5 is transferred over the receiver substrate 7 at a distance from the receiver substrate 7, and then a local vertical downward magnetic field 8 is continuously applied to the printed area (fig. 7 c). The bistable structure magnetic film in the printing area deforms and jumps, an impact force and a deformation extrusion force are generated on the element 5 in the area, and the element 5 is ejected from the stamp, so that the non-contact selective printing process is realized (fig. 7 d).

Claims

1. A magnetic control transfer seal based on a bistable structure is characterized by being formed by sequentially assembling a seal main body, a bistable structure magnetic film and an adhesive block arranged at the bottom of the bistable structure magnetic film from top to bottom; the seal body is provided with a cavity array penetrating through the bottom of the seal body; the fixing end of the bistable structure magnetic film is fixed by the seal main body and the adhesion block in an attaching mode, and the bistable structure magnetic film is in contact with an element after being deformed.

2. The magnetic control transfer stamp based on the bistable structure of claim 1, wherein the stamp body material is a nonmagnetic polymer, a nonmagnetic metal or an acrylic material.

3. The bistable-structure-based magnetically controlled transfer stamp of claim 1, wherein said adhesion blocks are of a single-layer or double-layer structure with adhesion.

4. The magnetron transfer printing stamp based on the bistable structure according to claim 1, wherein the material of the bistable structure magnetic thin film is a magnetic metal material or a mixed material formed by high polymer and magnetic particles, and the modulus of the bistable structure magnetic thin film is at least in the GPa level.

5. The magnetic control transfer stamp based on the bistable structure according to claim 1, wherein the stamp body material and the adhesive block material are both polydimethylsiloxane, and the content of the curing agent in the stamp body material is equal to or higher than that in the adhesive block material.

6. The magnetic control transfer stamp based on the bistable structure according to claim 4, wherein the bistable structure magnetic film is made of iron foil material.

7. A large-scale programmable transfer method, characterized in that, realized based on the stamp according to any one of claims 1 to 6, the steps are as follows:

when picking up, the seal is pressed on the component/substrate, and the component is picked up from the donor substrate by using the viscosity of the adhesive block;

during printing, under the continuous action of the magnetic field, the bistable structure magnetic film on the stamp deforms and jumps downwards to generate impact force and deformation extrusion force on the element, so that the element is separated from the stamp and is printed on a receiver substrate.

8. The large-scale programmable transfer printing method according to claim 7, wherein the external drive is a global magnetic field, and the stamp is driven to realize large-scale transfer printing; the external drive is a local magnetic field, and the stamp is driven to realize programmable patterned transfer printing.

9. The mass programmable transfer method according to claim 7, wherein the picking up is: a magnetic field is applied to a designated position of the stamp, the corresponding bistable structure magnetic film deforms and jumps, the release configuration is maintained, so that the corresponding position is kept in an adhesion-free state, when the stamp is in contact with an element on a donor substrate, the element except the position in the adhesion-free state can be picked up, and programmable selective pickup is realized.

10. The mass programmable transfer method of claim 7, wherein the printing is by: and applying a transient magnetic field to the designated position of the stamp to drive the bistable structure magnetic film to deform and jump, and generating impact force and deformation extrusion force on the element to separate the element from the stamp and print the element on a receiver substrate.