KR102229373B1 - Method for manufacturing flexible device, flexible device manufactured thereby, and junction device - Google Patents

Abstract

An aspect of the present invention is a method of manufacturing a flexible device, comprising: defining an electrode region of the device on a substrate; Forming a metal film on the substrate on which the electrode region of the device is defined; Forming a metal electrode pattern corresponding to the electrode region by removing a portion of the metal film; Forming a device by growing it on the metal electrode pattern; Forming a polymer film by applying a polymer solution on the metal electrode pattern and the device; And separating the metal electrode pattern and the polymer film having the device from the substrate.
According to the present invention, it is possible to manufacture a flexible device at low cost by using various materials in a relatively simple process, and to provide a flexible device and a bonding device having a simple structure that has excellent life characteristics and maintains stability even in mechanical deformation. have.

Description

Manufacturing method of flexible device, flexible device and bonding device manufactured thereby {METHOD FOR MANUFACTURING FLEXIBLE DEVICE, FLEXIBLE DEVICE MANUFACTURED THEREBY, AND JUNCTION DEVICE}

The present invention relates to a method of manufacturing a flexible device, a flexible device manufactured thereby, and a bonding device formed by bonding between the flexible devices.

Unlike a device formed on a hard substrate, a flexible device maintains the characteristics of the device even when repeated stress is applied, and has a property of being bent easily, so it can be attached to a flexible electronic component such as a flexible display, a touch screen, or a free curved surface. It can be used for sensors and the like.

According to the prior art, such a flexible device is generally manufactured in the form of a flexible film by mixing a functional ceramic/metal material with a flexible polymer material, and then made through a subsequent process such as electrode deposition. Alternatively, a device is implemented using a semiconductor process on a hard substrate or a specially designed wafer, more specifically, a semiconductor wafer composed of SOI (silicon on insulator), GaN, GaAs, etc., and is flexible through an etching process and a transfer process. Devices are also implemented on the substrate.

In the case of using such a conventional technique, a subsequent process such as metal electrode deposition and patterning, an expensive vacuum process, an etching process, etc. for implementing the function of the device should be used. In the case of the transfer process, since a sacrificial layer must be present in order to manufacture a flexible device, the use of materials that are vulnerable to the etching process is restricted. Considering that the etch rate between the sacrificial layer and the device should have a clear selectivity, fabrication of a flexible device through the prior art has many limitations in material selection. In addition, when bonding between devices is required, a complicated process and circuit design are required, so there is a limitation in practical application, and bonding is virtually impossible after transferring to a flexible substrate.

An aspect of the present invention is to provide a method of manufacturing a flexible device that simplifies the manufacturing process to reduce cost, has a wide range of material selection, and does not require a separate bonding process.

Another aspect of the present invention is to provide a flexible device having excellent life characteristics and not affected by mechanical deformation, and a bonding device using the same.

However, the problem to be solved by the present invention is not limited to the problems mentioned above, and other problems that are not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, an aspect of the present invention provides a method for manufacturing a flexible device, comprising: defining an electrode region of the device on a substrate; Forming a metal film on the substrate on which the electrode region of the device is defined; Forming a metal electrode pattern corresponding to the electrode region by removing a portion of the metal film; Forming a device by growing it on the metal electrode pattern; Forming a polymer film by applying a polymer solution on the metal electrode pattern and the device; And separating the metal electrode pattern and the polymer film having the device from the substrate.

Another aspect of the present invention provides a flexible device manufactured by the above manufacturing method.

Another aspect of the present invention provides a bonding device formed by bonding between flexible devices manufactured by the above manufacturing method.

According to the present invention, it is possible to manufacture a flexible device at low cost by using a variety of materials in a relatively simple process, and to provide a flexible device and a bonding device having a simple structure that has excellent life characteristics and maintains stability even under mechanical deformation. have.

1 is a manufacturing process diagram of a flexible device according to an embodiment of the present invention.
FIG. 2 is a diagram showing a binding force to a substrate by type of a metal thin film and mechanical properties of a polymer film according to an embodiment of the present invention.
3 is a diagram and a photograph showing the structure of a vertically aligned carbon nanotube-based supercapacitor according to an embodiment of the present invention.
4 is a partial view and a photograph of a manufacturing process of a flexible supercapacitor according to an embodiment of the present invention.
5 is a graph (b to f) showing a flexible supercapacitor (a) manufactured using a vertically oriented carbon nanotube-based supercapacitor and electrochemical characteristics thereof according to an embodiment of the present invention.
6 is a photograph of a mechanical deformation experiment on bending (a), folding (b), pulling (c), and rolling (d) of a flexible device manufactured according to an embodiment of the present invention.
7 is a pattern of a lithographic mask for manufacturing a resistor (a), an inductor (b), and a capacitor (c) according to an embodiment of the present invention.
FIG. 8 is a conceptual diagram (d) of a bonding process of various flexible devices (a to c) manufactured according to an embodiment of the present invention, and a bonding photograph (e) of these flexible devices.
9 is a bonded flexible device (a) and a voltage-time relationship graph (b) thereof, a bonded circuit, and voltage-time relationship graphs (c, d) thereof according to an embodiment of the present invention.

Throughout this specification, when a portion such as a layer, film, region, substrate, etc. is said to be "on" or "on" another component, it is not only when it is "directly over" another component, but also another component in the middle thereof. It should be construed to include the presence of elements.

Hereinafter, with reference to the accompanying drawings, a method for manufacturing a flexible device of the present invention, a flexible device and a bonding device manufactured thereby, will be described in detail so that those skilled in the art can easily implement the present invention.

The present invention relates to a technology for manufacturing a flexible device by separating a device manufactured on a substrate from a substrate using a polymer film. 1 shows an example of a manufacturing process diagram of the flexible device of the present invention.

First, a substrate is prepared and a metal electrode pattern is formed on the substrate. (Fig. 1(a))

The metal electrode pattern may function as a metal electrode layer, but is not limited thereto, but a metal selected from the group consisting of Mo, Au, Cu, Cr, Pt, Ni, Ti, and P; Or B, Si, Ge. It may be made of a metalloid selected from the group consisting of As, Sb, Te, and Po and an alloy of the metal.

To form the metal electrode pattern, an electrode region of the device is formed on a substrate through lithography, and a sputtering method such as radio frequency sputtering, an electron beam deposition method, an ion beam deposition method, a pulse-laser deposition method, a molecular beam deposition method, a chemical vapor deposition method , A metal film may be formed through a method such as an atomic layer deposition method.

Then, a metal electrode pattern corresponding to the electrode region may be formed through a lift-off process or the like.

As the substrate, an inorganic substrate or an organic substrate may be used.

The inorganic substrate may be made of glass, quartz, Al ₂ O ₃ , SiC, Si, GaAs, or InP, but is not limited thereto. As the organic substrate, Kepton foil, polyimide (PI), polyethersulfone (PES), polyacrylate (PAR, polyacrylate), polyether imide (PEI), polyethylene naphthalate (PEN, polyethylene naphthalate), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyarylate, polycarbonate (PC), cellulose triacetate (CTA), It may be selected from cellulose acetate propionate (CAP, cellulose acetate propionate), but is not limited thereto. It is more preferable that the inorganic substrate and the organic substrate are made of a hard material due to the characteristics of the present invention.

Subsequently, a device is formed on the metal electrode pattern. (Fig. 1(b))

The device may be made of carbon, metal, or metal oxide grown on the metal electrode pattern.

For example, a device made of carbon may be grown in the form of a carbon nanotube on a metal electrode pattern, but is not limited thereto.

The element made of the metal may be made of any one element selected from the group consisting of Mn, Co, Ni, Ti, V, Cr, Fe, Cu, Zn, Ru, Al, Sn, Rt, and Ir. It is not limited. In addition, the element made of the metal oxide is an oxide of any one element selected from the group consisting of Mn, Co, Ni, Ti, V, Cr, Fe, Cu, Zn, Ru, Al, Sn, Rt, and Ir. It may be made, but is not limited thereto.

The device may be implemented in the form of a resistor, a capacitor, an inductor, a super capacitor, a connector, a diode, or a transistor, but is not limited thereto.

After the device is grown on the metal electrode pattern, a polymer solution is applied and dried on the metal electrode pattern and the device to form a polymer film. (Fig. 1(c))

The polymer solution is PVA (polyvinyl alcohol), PMMA (polymethyl methacrylate), PVP (polyvinyl pyrolidone), PEO (polyethylene oxide), PVC (polyvinyl chloride), PAA (polyacrylic acid), and PAM (polyacrylamide). )-Based, PDMS (Polydimethylsiloxane)-based can be prepared by dissolving at least one polymer material selected from the group consisting of a solvent.

Examples of the solvent include chain ethers such as ethylene glycol dialkyl ether, propylene glycol dialkyl ether, polyethylene glycol dialkyl ether, and polypropylene glycol dialkyl ether; Alcohols such as methanol, ethanol, ethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, polyethylene glycol monoalkyl ether, and polypropylene glycol monoalkyl ether; Polyhydric alcohols such as ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, and glycerin; Nitrile compounds such as acetonitrile, glutarodinitrile, methoxyacetonitrile, propionitrile, and benzonitrile; Carbonate compounds such as ethylene carbonate and propylene carbonate; Heterocyclic compounds such as 3-methyl-2-oxazolidinone; Polar substances such as dimethyl sulfoxide and sulfolane; Water or a combination thereof or the like can be used. These may be used individually or may be used in combination of multiple types.

The polymer may be added to the solvent to form a gel-like solid phase.

In addition, an acid may be further added to the polymer solution.

Phosphoric acid may be exemplified as the acid. Moreover, both orthophosphoric acid and condensed phosphoric acid are contained in this phosphoric acid. By adjusting the amount of the acid added, the Young's modulus of the polymer film can be adjusted to control the degree of stretching of the polymer film.

It is preferable that the Young's modulus of the polymer film is 1 MPa to 500 MPa, because in this case, the adhesion between the polymer film and the metal electrode pattern can be maintained superior to the adhesion between the metal electrode pattern and the substrate.

To this end, the mass of the acid contained in the polymer solution is preferably adjusted to be less than or equal to the mass of the polymer. However, this mixing ratio may be somewhat adjusted depending on the type of polymer and the type of acid.

In addition, the polymer solution may further include an ion conductor or an ionic liquid. Examples of these include H ₃ PO ₄ , LiCl, Li ₂ SO ₄ , Na ₂ SO ₄ , H ₂ SO ₄ , KOH, NH ₄ SCN, H ₃ BO ₃ and the like.

The polymer membrane containing these may function as a gel electrolyte in an organic device. The gel electrolyte can be an alternative that can compensate for the deficiencies of the leakage and explosive properties of the liquid electrolyte and the low ionic conductivity of the solid electrolyte.

When the polymer film is formed, the metal electrode pattern and the polymer film having the device are separated from the substrate. (Fig. 1(d))

The polymer film has a high adhesive strength with the metal electrode pattern since the property was previously controlled in the manufacturing process, so that it can be easily detached from the substrate together with the metal electrode pattern and the device.

In the present invention, a flexible device manufactured by the above manufacturing method is provided, and a bonding device formed by bonding between the flexible devices is provided.

At this time, since the electrodes can be directly bonded together, a separate electric wire for connecting the electrodes does not act as an essential component. In a flexible device or a junction device, the polymer membrane may simultaneously perform a role as a base, a separator function, and an electrolyte function, thereby simplifying the configuration of the device and miniaturization.

The flexible device or junction device of the present invention maintains the characteristics of the device even when a repetitive stress is applied, and can be applied to various electronic devices such as a flexible energy storage device and a flexible next-generation display.

Hereinafter, the present invention will be described in detail through examples. However, the following examples are only examples for explaining the present invention in more detail, and do not limit the scope of the present invention.

[ Example ]

One. Flexible element Manufacturing and characterization evaluation

First, _{an electrode region of the device was formed on the SiO 2} substrate through lithography, and a metal film was formed using deposition equipment such as radio frequency sputtering and e-beam evaporator. A metal electrode pattern is formed by removing a part of the metal film through a lift-off process using an acetone bath, and a catalyst region for carbon nanotube growth is formed using lithography and lift-off processes. Made it. Vertically oriented carbon nanotubes were grown through chemical vapor deposition (CVD).

To prepare a solution for forming a polymer film, mix 1 g of polyvinyl alcohol with 10 g of water and dissolve by stirring in a 60-90°C bath for 3-12 hours, and 0-1 g in the dissolved polyvinyl alcohol solution. Phosphoric acid (phosphoric acid) was added and the mixture was stirred for an additional 3 to 12 hours.

After this solution was applied on the substrate prepared above, dried in an oven at room temperature or 40 to 60° C., the dried polymer film was mechanically removed from the substrate, and finally, a flexible device including a carbon nanotube-based device was manufactured.

Mechanical properties were evaluated for evaluating the adhesion between the metal electrode film and the substrate and the adhesion between the metal electrode film and the polymer film (FIG. 2). After depositing Cu, Mo, and Au on the SiO ₂ substrate, the adhesion of each metal film to the SiO ₂ substrate was evaluated and shown on the left y-axis of FIG. 2. The mass ratio of polyvinyl alcohol and phosphoric acid was adjusted from 1:0 to 1:1 to control the mechanical properties of the polymer membrane and evaluated and shown in the x-axis of FIG. 2. Finally, each metal film was formed on the SiO ₂ substrate, a solution in which the ratio of polyvinyl alcohol and phosphoric acid was adjusted was applied and dried, and the adhesion of the _{polymer film-metal film to the SiO 2 substrate was evaluated.} Shown on the axis. Au has _{low adhesion to SiO 2} , so it is easily detached from the substrate regardless of the mechanical properties of the polymer film, and Mo has higher adhesion than Au, but is easily detached from the substrate. In the case of Cu, it was observed that it was detached from the substrate only when a polymer film having a high Young's modulus was formed due to high adhesion. This means that by controlling the mechanical properties of the polymer film, the device formed on the metal thin film can be removed and made into a flexible device.

2. Supercapacitor manufacturing and characteristic evaluation

Vertically oriented carbon nanotubes were grown, and a supercapacitor was manufactured using a polyvinyl alcohol solution containing phosphoric acid as a gel electrolyte (FIGS. 3 and 4). The electrochemical characteristics of the supercapacitors manufactured on the substrate were evaluated through cyclic voltammetry (CV). It was observed that the characteristics of the manufactured supercapacitor were maintained even after separating the device from the substrate. (FIG. 5) Life characteristics also exhibited stable characteristics even when charging and discharging 2,000 times (FIG. 5(c)). It was confirmed that there was no change in characteristics of the flexible supercapacitor even with various mechanical deformations as shown in FIG. 6 (FIG. 5 ). For example, even at the time of 10,000 bending deformations (Fig. 5(e)) or stretching of 50% deformation (Fig. 5(f)), no deterioration in properties occurred.

3. Fabrication of junction elements and evaluation of characteristics

Prepare various patterns (FIG. 7) for manufacturing resistors, inductors, and capacitors, grow vertically oriented carbon nanotubes according to these patterns, and manufacture these devices using a polyvinyl alcohol solution containing phosphoric acid. After separating from the substrate, flexible resistors, inductors, and capacitors were finally manufactured. After aligning the devices manufactured as shown in FIG. 8, by bonding these devices to each other using only the adhesive force of the polymer film, a circuit in which a resistor, an inductor, and a capacitor are electrically connected was implemented. In addition, as shown in Fig. 9, five flexible supercapacitors were connected in series with each other, charged with a solar cell, and then a light emitting device was driven, and the manufactured flexible resistors, capacitors, and electrical connectors were joined together to form RC A circuit was formed to prepare a high pass filter and a low pass filter. The devices thus formed showed normal circuit behavior even during bonding, and were not affected by mechanical deformation such as twisting.

4. Review the results

Since the conventional etching process for manufacturing the flexible device was not used, the choice of materials was widened, and the convenience in the process was increased. In addition, as bonding between devices, which is difficult to access with the existing deposition process, is possible, it has become possible to manufacture a flexible composite device.

Claims (9)

In the method of manufacturing a flexible device,
Defining an electrode region of the device on the substrate;
Forming a metal film on the substrate on which the electrode region of the device is defined;
Forming a metal electrode pattern corresponding to the electrode region by removing a portion of the metal film;
Forming a device by growing it on the metal electrode pattern;
Forming a polymer film by applying a polymer solution on the metal electrode pattern and the device; And
And separating the metal electrode pattern and the polymer film having the device from the substrate.
The method of claim 1,
The metal film is a metal selected from the group consisting of Mo, Au, Cu, Cr, Pt, Ni, Ti, and P; Or B, Si, Ge. As, Sb, Te, Po, a metalloid selected from the group consisting of and consisting of an alloy of the metal, a method of manufacturing a flexible device.
The method of claim 1,
The device is made of carbon, metal, or metal oxide grown on the metal electrode pattern, the method of manufacturing a flexible device.
The method of claim 1,
The polymer solution contains a polymer, and the polymer is a polyvinyl alcohol (PVA) system, a polymethyl methacrylate (PMMA) system, a polyvinyl pyrolidone (PVP) system, a polyethylene oxide (PEO) system, a polyvinyl chloride (PVC) system, and a polyacrylic (PAA) system. acid), PAM (Polyacrylamide), and PDMS (Polydimethylsiloxane) is one selected from the group consisting of, a method of manufacturing a flexible device.
The method of claim 4,
The polymer solution further comprises an acid (acid), the method of manufacturing a flexible device.
The method of claim 4,
The polymer solution further comprises an ion conductor or an ionic liquid.
The method of claim 5,
By adjusting the amount of acid added so that the adhesion between the polymer film and the metal electrode pattern is superior to the adhesion between the metal electrode pattern and the substrate, the Young's modulus of the polymer film is 1 MPa to 500 MPa. , Manufacturing method of a flexible device. delete delete

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