KR20180085218A - Adhensive thin film and method for adhensive of substrate using the same - Google Patents

Abstract

The present invention relates to an adhesive thin film and a method of bonding substrates using the adhesive thin film, and more specifically, to an adhesive thin film which comprises a copolymer formed of glycidyl methacrylate (GMA) and dimethyl amino ethyl methacrylate (DMAEMA), is applicable to various substrates, and is very thin but cross-linked to the substrates strongly and rapidly; and a method of bonding the substrates using the adhesive thin film. The adhesive thin film has been confirmed to be usefully used in depositing a polymer thin film on various substrates such as paper, fibers and separation membranes which are weak to mechanical and chemical impacts without damaging the substrates at all compared to an existing liquid phase process since the adhesive thin film is deposited in a gas phase and formed at low temperatures. In addition, it is possible to confirm that monomers which are not mixed due to constituents or a surface energy difference generated in liquid phase deposition are uniformly produced into a copolymer since the adhesive thin film is deposited in a gas phase. Further, it has been confirmed that the adhesive thin film is able to be bonded within a short time, has thermal stability at high temperatures, and is chemically stable even in acetone, toluene, DMF, THF, and strongly acidic and basic solutions. The adhesive thin film has been also confirmed to be successfully bonded to various flexible substrates such as latex, PEN and the like, and not to have an effect on flexibility of the substrates even after the adhesive thin film is bonded to the substrates.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an adhesive thin film and a method of adhering a substrate using the adhesive thin film.

(GMA) and dimethylaminoethyl methacrylate (DMAEMA). The present invention relates to a method for bonding a substrate using the adhesive thin film, and more particularly, And which is very thin but strong and rapidly crosslinkable, and a method of bonding substrates using the same.

Adhesive is a material that can fix two surfaces together. It is widely used in our life because of its strong adhesive force, applicability to various substrates, and low price. With the progress of studies on imparting mechanical flexibility to various structures through the use of adhesives, much attention has been focused on the field of adhesion of microfluidic devices, flexible element seal films and the like. Therefore, while maintaining the adhesive strength of the adhesive, mechanical flexibility and optical properties after bonding and stability under various conditions are required.

Conventional adhesives include liquid adhesives which are cured by ultraviolet rays or heat. However, since the conventional liquid adhesive has a thick thickness of several tens of microns, the flexibility after curing is seriously deteriorated.

Adhesives using wet processes such as spin coating or dip coating have been developed for thin adhesives, but still have a thickness of a few microns, and simultaneously have problems such as damage to the substrate, impossibility for complicated structures, and the like.

Therefore, the present inventors have made intensive efforts to develop a dry adhesive capable of solving the limitations of the conventional methods, and as a result, the adhesive of the present invention is deposited at the vapor phase and is carried out at a low temperature, It can be useful for depositing polymer thin films on various substrates that are weak to mechanical and chemical impacts such as paper, fiber, and separator, and because of the deposition on the gas phase, the surface energy difference caused by liquid deposition or monomers that are not mixed by the constituent material It was confirmed that the copolymer was uniformly produced and the present invention was completed.

It is an object of the present invention to provide a method of bonding a substrate using an iCVD process.

It is another object of the present invention to provide an adhesive thin film using an iCVD process.

(GMA) and dimethyl amino ethyl methacrylate (DMAEMA) between a first surface and a second surface which are opposed to each other, And an initiator; (b) pyrolyzing the initiator by injecting heat to form a free radical; (c) forming a GMA-DMAEMA copolymer through polymerization of GMA and DMAEMA using the free radicals; and depositing a GMA-DMAEMA copolymer on the first and second surfaces by an iCVD process to form a GMA-DMAEMA copolymer Forming a coalesced thin film; And (d) thermally curing the GMA-DMAEMA copolymer thin film to form an adhesive thin film.

The present invention also provides a method of manufacturing a semiconductor device, comprising: (a) providing a first surface; (b) a second surface opposite the first surface; And (c) an adhesive thin film positioned between the copolymer thin film located on the lower surface of the first surface and the copolymer thin film located on the upper surface of the second surface, wherein the adhesive thin film adheres the first surface and the second surface, The thin film was prepared by heating a GMA-DMAEMA copolymer thin film composed of glycidyl methacrylate (GMA) and dimethyl amino ethyl methacrylate (DMAEMA) on the first and second surfaces, And the adhesive thin film is produced by curing.

Since the adhesive thin film according to the present invention is vapor-deposited at a low temperature, the polymer thin film is deposited on a variety of substrates which are less susceptible to mechanical and chemical impacts such as paper, fiber and separator, And it is confirmed that the monomers which are not mixed by the constituent materials are uniformly made into the copolymer because of the difference in surface energy generated in the liquid phase deposition due to vapor deposition. In addition, it is possible to bond in a short time, and it is confirmed that it is chemically stable even at high temperature, thermal stability and acetone, toluene, DMF, THF, strong acidic and strong basic solution and can be successfully adhered on various flexible substrates such as latex and PEN And it was confirmed that even after bonding, the flexibility was not affected.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 provides a schematic diagram of a process for bonding using a copolymer comprising GMA and DMAEMA of the present invention.
2 shows FTIR and XPS analysis results of a copolymer according to an embodiment of the present invention.
FIG. 3 shows the results of measuring the shear strength and peel strength of the copolymer according to an embodiment of the present invention.
FIG. 4 is a graph showing the results of confirming optical and mechanical properties of a copolymer according to an embodiment of the present invention after curing.
5 shows the results of confirming stability and mechanical stability of the adhesive performance of the adhesive thin film according to an embodiment of the present invention.
FIG. 6 shows the result of confirming flexibility after depositing a copolymer according to an embodiment of the present invention on various substrates.

The present invention can be all accomplished by the following description. It is to be understood that the following description is only illustrative of preferred embodiments of the invention, but the invention is not necessarily limited thereto. It is to be understood that the accompanying drawings are included to provide a further understanding of the invention and are not to be construed as limiting the present invention. The details of the individual components may be properly understood by reference to the following detailed description of the related description.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In general, the nomenclature used herein is well known and commonly used in the art.

The adhesive according to the present invention is manufactured by chemical vapor deposition (iCVD). Since the vapor deposition is performed at a low temperature, the substrate is free from any damage to the substrate compared with the conventional liquid phase process. And it is confirmed that the monomers are uniformly made into a copolymer because of vapor deposition at the vapor phase. In addition, it is possible to produce an adhesive thin film which can be adhered within a short time, and which has a thermostability at a high temperature and a chemically stable copolymer in various solutions.

Thus, in one aspect, the present invention relates to a composition comprising (a) glycidyl methacrylate (GMA) and dimethyl amino ethyl methacrylate (DMAEMA) between the first surface and the second surface, ) And an initiator; (b) pyrolyzing the initiator by injecting heat to form a free radical; (c) forming a GMA-DMAEMA copolymer through polymerization of GMA and DMAEMA using the free radicals; and depositing a GMA-DMAEMA copolymer on the first and second surfaces by an iCVD process to form a GMA-DMAEMA copolymer Forming a coalesced thin film; And (d) thermally curing the GMA-DMAEMA copolymer thin film to form an adhesive thin film.

In another aspect, the present invention provides a method of manufacturing a semiconductor device, comprising: (a) providing a first surface; (b) a second surface opposite the first surface; And (c) an adhesive thin film positioned between the copolymer thin film located on the lower surface of the first surface and the copolymer thin film located on the upper surface of the second surface, wherein the adhesive thin film adheres the first surface and the second surface, The thin film was prepared by heating a GMA-DMAEMA copolymer thin film composed of glycidyl methacrylate (GMA) and dimethyl amino ethyl methacrylate (DMAEMA) on the first and second surfaces, And curing the adhesive thin film.

FIG. 1 is a schematic view showing the process of bonding using a copolymer composed of GMA (glycidyl methacrylate) and DMAEMA (dimethyl amino ethyl methacrylate) of the present invention. The copolymer of GMA and DMAEMA is deposited on both substrates by iCVD Followed by heating at 80 ° C for 10 minutes with pressure. In this process, the tertiary amine of DMAEMA initiates the ring opening reaction of the epoxy, and the resulting radical initiates the ring opening of the other epoxy to cause a self-crosslinking reaction. In addition, it is possible to deposit uniformly on a substrate of various structures which is an advantage of iCVD, and it is possible to adhere to a channel of several hundreds of nanometers by minimizing structural damage as shown in the figure.

In the present invention, TBPO (t-butylperoxide) or benzophenone is preferable as the initiator, but the kind of the initiator that can be used in the present invention is not limited by the above examples.

In the present invention, only the heat applied from the gas phase reactor filament is sufficient for the reaction used for the free radicalization of the initiator. Therefore, the processes used in the embodiments of the present invention can be sufficiently performed even at low power. In addition, since the reaction pressure in the gas phase reactor is in the range of 50 to 2,000 mTorr, a strict high vacuum condition is not required, and therefore, the process can be performed by a simple rotary pump instead of a high vacuum pump.

The physical properties of the polymer thin film obtained through the process can be easily controlled by controlling the process parameters of chemical vapor deposition (iCVD) including an initiator. That is, by adjusting the process pressure, time, temperature, flow rate of the initiator and monomer, filament temperature, and the like, it is possible to control physical properties such as the molecular weight of the polymer thin film, the desired thickness of the thin film,

The 'initiator' of the present invention is not particularly limited as long as it is a substance capable of decomposing by the supply of heat in the reactor to form a free radical, which can activate the monomer. Preferably, the initiator may be a peroxide, for example the initiator may be TBPO (tert-butyl peroxide). TBPO is a volatile substance having a boiling point of about 110 ° C, which pyrolyzates around 150 ° C. On the other hand, the amount of the initiator moiety can be added in an amount known in the art in an amount required for a conventional polymerization reaction, and may be, for example, 0.5 to 5 mol%, but is not limited to the above range, Can be written down.

By controlling the flow rate of the monomers introduced into iCVD, a copolymer having various compositions was prepared, and an adhesive having an optimum adhesion performance using the copolymer was developed. While showing strong adhesion performance, it showed excellent stability under various conditions and applied to various flexible substrates at the same time. It is expected that this technology will be applied in various ways to replace the conventional adhesive materials.

In the present invention, the adhesive thin film preferably has a thickness of 10 nm to 1000 nm, most preferably 50 nm to 600 nm.

In the present invention, the adhesive thin film has a first surface; A second surface opposite the first surface; And an adhesive thin film positioned between the copolymer thin film located on the lower surface of the first surface and the copolymer thin film located on the upper surface of the second surface and bonding the first surface and the second surface,

A first surface; A second surface opposite the upper surface of the upper limb; A third surface opposite the second surface; A first adhesive thin film positioned between the copolymer thin film located on the lower surface of the first surface and the copolymer thin film located on the upper surface of the second surface and bonding the first surface and the second surface; And a second adhesive thin film positioned between the copolymer thin film located on the lower surface of the second surface and the copolymer thin film located on the upper surface of the third surface and bonding the second surface to the third surface, But is not limited thereto.

In the present invention, the substrate can be used on a flexible substrate or a glass substrate. Examples of the flexible substrate include latex, polyethylene naphthalate (PEN), polydimethylsiloxane (PDMS) (PET), polymethylmethacrylate (PMMA), polycarbonate (PC), polyethylene sulfone (PES), and the like. The organic electroluminescent device implemented thereon may be formed of an organic material The organic light emitting diode (OLED), organic solar cells (Organic Photovoltaic Cells) (oPVs), organic thin film transistors (oTFTs), and the like are typical examples of the device. , And various other types of organic electronic products.

In addition, since the iCVD process is a complete drying process, the bonding method according to one embodiment of the present invention can be applied to various types of substrates, and particularly, substrates susceptible to external mechanical and chemical impacts can be easily applied. For example, the present invention can be applied to substrates such as cloths and fabrics which are highly susceptible to damage by a liquid-phase process, and can also be applied to substrates easily deformed by a solvent such as a contact lens. Various hydrogel materials Can also be used effectively.

In the present invention, the thermosetting step is preferably carried out at a temperature of 70 ° C to 90 ° C, more preferably 80 ° C to 85 ° C.

In the present invention, dimethylamine ethyl methacrylate (DMAEMA), which is a tertiary amine, serves as a catalyst to cause a ring opening reaction of an epoxy, and a radical generated at this time causes a ring opening of another epoxy to react Causing a crosslinking reaction. Therefore, it was confirmed that the copolymer of the present invention can be adhered within a short time due to the reaction, and that the thermosetting step is preferably performed for 1 minute to 60 minutes, and the adhesive performance is stable even at a short bonding time of 3 minutes to 10 minutes .

Conventional liquid adhesives have a serious problem of a decrease in flexibility after curing due to a thick thickness of several tens of microunits, and adhesives using a wet process such as spin coating or dip coating have a thickness of several micro-meters, And it was impossible to apply it to the

However, the adhesive thin film of the present invention exhibited excellent adhesive performance even in the case of a very thin thickness of 50 nm to 600 nm, and it was confirmed that the substrate was not damaged due to vapor deposition, and problems such as flexibility were not caused.

Hereinafter, the present invention will be described in more detail with reference to Examples. It will be apparent to those skilled in the art that these embodiments are merely illustrative of the present invention and that the scope of the present invention is not limited to these embodiments.

Example  One: GMA  And By DMAEMA  Preparation of Copolymers Constituted

In this Example, a copolymer composed of GMA and DMAEMA was prepared. The reaction was carried out in an iCVD chamber (Daeki Hi-Tech co) using a monomer GMA (97%, Aldrich, USA), DMAEMA (95%, TCI, Japan) and an initiator tert-butyl peroxide (TBPO, , Ltd) to prepare a copolymer of GMA and DMAEMA through free radical polymerization. To initiate the free radical polymerization, the filaments inside the chamber were maintained at 180 캜 and the temperature of the substrate was maintained at 30 캜. The pressure inside the chamber during the polymerization was fixed at 160 mTorr. In this process, the copolymer was prepared by controlling the flow rates of GMA and DMAEMA from 4: 1 to 1: 2. The copolymer was prepared by mixing G-D1 (4: 1), G-02 (2: 1) and G-D4 (1: 2).

Example  2: FTIR  And XPS  analysis

In this Example, the FTIR and XPS analyzes of the copolymer prepared in Example 1 were carried out.

FTIR analysis was performed using ALPHA FT-IR (Bruker optics). As shown in FIG. 2- (a), the pGMA composition in the graphs of pGMA, G-D1, G-D2, G-D3 and G- The intensity of the epoxy functional groups (759, 847 and 907 cm ^{- 1} ) of pGMA decreased with increasing size. Conversely, the intensity of the amine functional group (2767 and 2819 cm ^{- 1} ), which is the functional group of pDMAEMA, was found to increase.

The XPS analysis was performed using a Sigma Probe Multipurpose XPS (Thermo VG Scientic). As shown in FIGS. 2 (b) and 2 (c), the same tendency as the FTIR result was obtained. The composition of epoxy and amine could be obtained from the combination (Fig. 2- (d)).

As a result, it has been confirmed that a variety of compositions can be prepared by controlling the introduction flow rate of GMA and DMAEMA using the iCVD process.

Example  3: Analysis of shear strength and peel strength

In this Example, the shear strength and peel strength of the copolymer prepared in Example 1 were analyzed.

Shear strength and peel strength were analyzed using UTM. Shear strength was measured with two glass slides and peel strength with two PETs. A comparison between the G-D1 to G-D4 adhesives prepared in Example 1 and the pGMA single glue as a comparative group was carried out through analysis of the two adhesive strengths. The adhesive of the copolymer at 85 DEG C, the pGMA single- Lt; 0 > C. As a result, it was confirmed that the adhesive of the G-D1 copolymer having the lowest amount of pDMEAMA showed the strongest adhesive force (Figs. 3- (a), (b)). In addition, the curing time of each copolymer varied from 3 minutes to 120 minutes. As a result, it was found that the G-D1 copolymer showed the best adhesion even in a short time of 3 minutes 3- (c)). The curing time of the G-D1 copolymer was fixed to 10 minutes, and then the thickness was reduced from 600 nm to 50 nm. As a result, the adhesive performance was secured even at 50 nm (Fig. 3- (d)).

Example  4: Analysis of optical and mechanical properties of G-D1

In this example, the optical and mechanical properties of the copolymer and G-D1 prepared in Example 1 were analyzed to confirm the polymer stability.

FIG. 4 shows the results of optical and mechanical properties of G-D1 before and after curing at 85 ° C for 15 minutes after depositing a copolymer using iCVD.

The optical properties were measured using a Spectroscopic Ellipsometer (M2000D, J.A. Woollam, Lincoln, USA) and the refractive index was measured using a UV-3600 UV-VIS-NIR Spectrophotometer (Shimadzu, Japan). As shown in Figs. 4- (a) and (b), it was confirmed that even after the application of heat, the optical characteristics, that is, the transmittance and the refractive index were almost unchanged.

Mechanical properties of the surface were measured using AFM, The hardness of the cornea was measured using a Nano Indentation System (Nano Indenter XP, MTS). As shown in Figs. 4- (c) and (d), it was confirmed that even after heat application, the flatness of the surface was not significantly affected, and the hardness of the polymer thin film, But it is confirmed that it is applicable to a flexible substrate because the difference is not large.

Example  5: Analysis of chemical and mechanical properties of adhesives

In this example, the adhesive film containing the copolymer prepared in Example 1, G-D1 Chemical and mechanical properties.

An adhesive was prepared using G-D1 prepared in Example 1, and a pGMA single adhesive was used as a comparative group.

The shear strength before and after the heat treatment for 20 hours at 200 ° C was measured to confirm the chemical properties of the adhesive thus prepared. Acetone, toluene, DMF, THF, strongly acidic (pH = 2) Solution for 20 hours and then the shear strength was measured. As a result, it was confirmed that, as shown in Figs. 5- (a) and (b), excellent thermal stability and excellent chemical stability from the crosslinking by the amine composition were confirmed.

Also, flexing and folding tests were carried out to confirm the mechanical stability and the peel strength was measured. 5 (c) and (d), flexing test was performed to confirm flexibility. Even when heat and humidity (85 ° C., 85 RH) were applied after folding, Respectively.

Example  6: Application of adhesives to various substrates

In this embodiment, an adhesive using the G-D1 fabricated in Example 1 was deposited on various substrates such as latex, PET, PEN, and PDMS. The effect of the adhesive on the adhesive strength and flexibility was confirmed.

As shown in Fig. 6, it was confirmed that even after bonding a thin and flexible substrate, flexibility was not affected.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will readily appreciate that many modifications are possible, will be. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (8)

(a) providing glycidyl methacrylate (GMA) and dimethyl amino ethyl methacrylate (DMAEMA) and an initiator between first and second surfaces facing each other;
(b) pyrolyzing the initiator by injecting heat to form a free radical;
(c) forming a GMA-DMAEMA copolymer through polymerization of GMA and DMAEMA using the free radicals; and depositing a GMA-DMAEMA copolymer on the first and second surfaces by an iCVD process to form a GMA-DMAEMA copolymer Forming a coalesced thin film; And
(d) thermally curing the GMA-DMAEMA copolymer thin film to form an adhesive thin film.
The method of claim 1, wherein the initiator is t-butyl peroxide (TBPO) or Benzophenone.
The bonding method according to claim 1, wherein the copolymer has a GMA: DMAEMA = 4: 1 to 1: 2 (mass ratio).
(a) a first surface;
(b) a second surface opposite the first surface; And
(c) an adhesive thin film positioned between the copolymer thin film located on the lower surface of the first surface and the copolymer thin film located on the upper surface of the second surface, and bonding the first surface and the second surface,
The adhesive thin film was formed on the first and second surfaces by using a GMA-DMAEMA copolymer thin film composed of glycidyl methacrylate (GMA) and dimethyl amino ethyl methacrylate (DMAEMA) The adhesive thin film being formed by thermosetting.
The adhesive thin film according to claim 4, wherein the GMA-DMAEMA copolymer is formed through a polymerization reaction of GMA and DMAEMA using a free radical formed by pyrolysis of an initiator.
6. The adhesive film of claim 5, wherein the initiator is t-butyl peroxide (TBPO) or Benzophenone.
The adhesive thin film according to claim 4, wherein the copolymer has a GMA: DMAEMA = 4: 1 to 1: 2 (mass ratio).
The adhesive thin film according to claim 4, wherein the thickness of the adhesive thin film is 10 nm to 1000 nm.

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