U.S. patent application number 16/654096 was filed with the patent office on 2020-02-13 for multilayer encapsulation thin-film.
This patent application is currently assigned to Research & Business Foundation Sungkyunkwan University. The applicant listed for this patent is Research & Business Foundation Sungkyunkwan University, Samsung Display Co., Ltd.. Invention is credited to Heeyeop CHAE, Sungmin CHO, Ho Kyoon CHUNG, Choelmin JANG, Sang Joon SEO, Seung Woo SEO.
Application Number | 20200048763 16/654096 |
Document ID | / |
Family ID | 51789484 |
Filed Date | 2020-02-13 |
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United States Patent
Application |
20200048763 |
Kind Code |
A1 |
JANG; Choelmin ; et
al. |
February 13, 2020 |
MULTILAYER ENCAPSULATION THIN-FILM
Abstract
A multilayer encapsulation thin-film and a method and apparatus
for preparing a multilayer encapsulation thin-film are provided.
The multilayer encapsulation thin-film includes an inorganic thin
film that includes a metal oxide, and an organic thin film that
includes a polymer and is formed on the inorganic thin film, where
the inorganic thin film and the organic thin film are alternately
stacked in multiple layers
Inventors: |
JANG; Choelmin; (Yongin-si,
KR) ; CHO; Sungmin; (Gunpo-si, KR) ; CHUNG; Ho
Kyoon; (Yongin-si, KR) ; CHAE; Heeyeop;
(Anyang-si, KR) ; SEO; Sang Joon; (Seoul, KR)
; SEO; Seung Woo; (Hwaseong-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Research & Business Foundation Sungkyunkwan University
Samsung Display Co., Ltd. |
Suwon-si
Yongin-si |
|
KR
KR |
|
|
Assignee: |
Research & Business Foundation
Sungkyunkwan University
Suwon-si
KR
Samsung Display Co., Ltd.
Yongin-si
KR
|
Family ID: |
51789484 |
Appl. No.: |
16/654096 |
Filed: |
October 16, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14260815 |
Apr 24, 2014 |
|
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16654096 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
Y10T 428/31855 20150401;
H01L 51/5256 20130101; Y02E 10/549 20130101; C23C 16/44 20130101;
Y10T 428/269 20150115; Y10T 428/31935 20150401; Y10T 428/31663
20150401; C23C 28/00 20130101; C23C 28/42 20130101; H01L 51/448
20130101 |
International
Class: |
C23C 16/44 20060101
C23C016/44; C23C 28/00 20060101 C23C028/00; H01L 51/44 20060101
H01L051/44; H01L 51/52 20060101 H01L051/52 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 30, 2013 |
KR |
10-2013-0047933 |
Feb 11, 2014 |
KR |
10-2014-0015730 |
Claims
1. An apparatus for producing a multilayer encapsulation thin-film
comprising: a substrate loading unit on which a substrate is
loaded; an inorganic thin film deposition unit to deposit an
inorganic thin film on the substrate; and an organic thin film
deposition unit to deposit an organic thin film on the inorganic
thin film, wherein the inorganic thin film deposition unit and the
organic thin film deposition unit are sequentially connected to
each other, and the substrate loading unit is alternately moved to
the inorganic thin film deposition unit and the organic thin film
deposition unit, so that the inorganic thin film and the organic
thin film are alternately deposited on the substrate.
2. The apparatus of claim 1, wherein the organic thin film
deposition unit further comprises a UV curing unit.
3. The apparatus of claim 1, wherein a plurality of inorganic thin
film deposition units are sequentially connected to the organic
thin film deposition unit through more than one connection.
4. The apparatus of claim 3, wherein the plurality of inorganic
thin film deposition units and the organic thin film deposition
unit are alternately arranged.
5. The apparatus of claim 3, wherein the organic thin film
deposition unit is arranged at a terminus of the sequential
connection of units.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application divisional of U.S. application Ser. No.
14/260,815 filed on Apr. 24, 2014 which claims the benefit under 35
USC 119(a) to Korean Patent Application No. 10-2014-0015730 filed
on Feb. 11, 2014 and Korean Patent Application No. 10-2013-0047933
filed on Apr. 30, 2013, in the Korean Intellectual Property Office,
the disclosures of which are incorporated herein by reference for
all purposes.
BACKGROUND
1. Field
[0002] The following description relates to a multilayer
encapsulation thin-film and a method and apparatus for preparing
the multilayer encapsulation thin-film.
2. Description of Related Art
[0003] An organic device such as an organic light emitting diode
(OLED), an organic photovoltaic cell (OPV cell), and the like
contains an organic material and a metallic electrode which is
easily oxidized and has a low work function in order to facilitate
charge transfer with the organic material. Thus, it is very
vulnerable to oxidative materials such as water vapor or oxygen.
Therefore, if it is exposed to oxygen or steam, power reduction or
early deterioration of performance may occur. In order to prevent
deterioration, it is necessary to use an encapsulation method
capable of completely blocking an organic device from water vapor
or oxygen.
[0004] Currently, most organic devices are produced on a glass
substrate, and for complete encapsulation of these devices, an
encapsulation method of covering at an upper unit of an organic
device with a glass or metal can has been used. Here, the glass or
metal can is bonded using glass frit or an UV-curing polymer, so
that the organic device can be completely separated from external
water vapor or oxygen. After encapsulation, in order to remove
water vapor and oxygen which may remain on the upper unit of the
organic device, a desiccant may be used within the glass or metal
can.
[0005] Since organic devices have flexibility due to the nature of
an organic material, attempts to make the most of this property
have been made. In order to do so, the organic devices need to be
produced using a substrate made of plastic, metal foil, or flexible
glass, and an encapsulation material also needs to be flexible.
Particularly, in the case of a flexible organic device using a
substrate made of plastic, a process temperature is limited. Thus,
an encapsulation method needs to be performed through a
low-temperature process. An encapsulation thin film method has been
developed for this purpose. The encapsulation thin film method is a
method of blocking an organic device from water vapor or oxygen by
directly depositing an inorganic thin film or an organic thin film
on a surface of the organic device and does not require a sealant
for edge sealing or an absorbent/desiccant, and, thus, a thin
device can be produced by this method.
[0006] Recently, there have been made attempts to utilize a
multilayer organic-inorganic hybrid thin film by stacking an
inorganic material and an organic material in multiple layers. As
an inorganic material used for such a multilayer organic-inorganic
thin film, a metal oxide such as an aluminum oxide has been used.
Further, as an organic material, an acrylic polymer polymerized by
spray-coating an acrylic monomer followed by UV-curing has been
used. Korean Patent No. 10-2011-0049477 relates to a multilayer
thin film for encapsulation and a preparing method thereof, and
describes a multilayer encapsulation film including a protective
layer made of an aluminum oxide, single or double blocking layers
made of silicon nitride, and a mechanical protective layer formed
of silicon dioxide stacked in sequence. However, in such multilayer
encapsulation film, when the protective layer and the blocking
layer are formed, thin films are formed by atomic layer deposition
(ALD) and chemical vapor deposition (CVD), respectively, and then,
a silicon oxide solution in a sol-gel state is discharged by a
spraying method to form the mechanical protective layer. Since
deposition of the thin films are carried out in separate
apparatuses, consecutive transfer needs to be made and it takes a
significant amount of time to deposit the thin films. Therefore,
such a method has limitation in that the overall processing time is
increased.
[0007] In order to avoid the complexity, when a multilayer
encapsulation thin-film is formed, there has been demanded
development of a process that is simplified and requires a reduced
overall processing time.
SUMMARY
[0008] This Summary is provided to introduce a selection of
concepts in a simplified form that are further described below in
the Detailed Description. This Summary is not intended to identify
key features or essential features of the claimed subject matter,
nor is it intended to be used as an aid in determining the scope of
the claimed subject matter.
[0009] In one general aspect, there is provided a multilayer
encapsulation thin-film comprising: an inorganic thin film that
comprises a metal oxide; and an organic thin film that comprises a
polymer and is formed on the inorganic thin film, wherein the
inorganic thin film and the organic thin film are alternately
stacked in multiple layers.
[0010] In another general aspect, there is provided a multilayer
encapsulation thin-film wherein the metal oxide comprises a member
selected from the group consisting of aluminum oxide, zirconium
oxide, zinc oxide, silicon oxide, silicon nitride, silicon carbide,
silicon oxynitride, silicon oxycarbide, and combinations
thereof.
[0011] In another general aspect, there is provided a multilayer
encapsulation thin-film wherein the polymer comprises a member
selected from the group consisting of a plasma polymer, an acrylic
polymer, and combinations thereof.
[0012] In another general aspect, there is provided a multilayer
encapsulation thin-film wherein the plasma polymer comprises a
member selected from the group consisting of hexamethyl disiloxane,
furan, hexane and combinations thereof.
[0013] In another general aspect, there is provided a multilayer
encapsulation thin-film wherein the acrylic polymer comprises a
member selected from the group consisting of an acrylate, a
urethane acrylate, a polyacrylate, a polyalkylacrylate, a
polyacrylamide, an ethylene-acrylic acid copolymer, and
combinations thereof.
[0014] In another general aspect, there is provided a multilayer
encapsulation thin-film wherein a single layer of the inorganic
thin film has a thickness in a range of from 0.1 nm to 20 nm.
[0015] In another general aspect, there is provided a multilayer
encapsulation thin-film wherein a single layer of the organic thin
film has a thickness in a range of from 20 nm to 2 .mu.m.
[0016] In another general aspect, there is provided a multilayer
encapsulation thin-film wherein the multiple layers comprise 2 to
200 dyads of the inorganic thin film and the organic thin film.
[0017] In yet another general aspect, there is provided a method of
preparing a multilayer encapsulation thin-film, the method
comprising: forming an inorganic thin film comprising a metal oxide
on a substrate; and forming an organic thin film comprising a
polymer on the inorganic thin film, wherein the forming the
inorganic thin film on the substrate and the forming the organic
thin film comprising the polymer on the inorganic thin film are
alternately carried out, so that the inorganic thin film and the
organic thin film are alternately stacked.
[0018] In another general aspect, there is provided a method of
preparing a multilayer encapsulation thin-film wherein the forming
of the inorganic thin film is carried out by atomic layer
deposition.
[0019] In another general aspect, there is provided a method of
preparing a multilayer encapsulation thin-film wherein the forming
of the organic thin film is carried out by chemical vapor
deposition or atomic layer deposition.
[0020] In another general aspect, there is provided a method of
preparing a multilayer encapsulation thin-film wherein the forming
of the organic thin film is carried out by coating an acrylic
monomer on the inorganic thin film and then UV-curing the
coating.
[0021] In another general aspect, there is provided a method of
preparing a multilayer encapsulation thin-film wherein the forming
of the inorganic thin film and/or the forming of the organic thin
film are carried out at a temperature in a range of about
20.degree. C. to about 120.degree. C.
[0022] In another general aspect, there is provided a method of
preparing a multilayer encapsulation thin-film wherein the atomic
layer deposition comprises spatially arranging raw materials for
the inorganic thin film on a moving substrate.
[0023] In yet another general aspect, there is provided an
apparatus for producing a multilayer encapsulation thin-film
comprising: a substrate loading unit on which a substrate is
loaded; an inorganic thin film deposition unit to deposit an
inorganic thin film on the substrate; and an organic thin film
deposition unit to deposit an organic thin film on the inorganic
thin film, wherein the inorganic thin film deposition unit and the
organic thin film deposition unit are sequentially connected to
each other, and the substrate loading unit is alternately moved to
the inorganic thin film deposition unit and the organic thin film
deposition unit, so that the inorganic thin film and the organic
thin film are alternately deposited on the substrate.
[0024] In another general aspect, there is provided an apparatus
for producing a multilayer encapsulation thin-film, wherein the
organic thin film deposition unit further comprises a UV curing
unit.
[0025] In another general aspect, there is provided an apparatus
for producing a multilayer encapsulation thin-film wherein a
plurality of inorganic thin film deposition units are sequentially
connected to the organic thin film deposition unit through more
than one connection.
[0026] In another general aspect, there is provided an apparatus
for producing a multilayer encapsulation thin-film wherein the
plurality of inorganic thin film deposition units and the organic
thin film deposition unit are alternately arranged.
[0027] In another general aspect, there is provided an apparatus
for producing a multilayer encapsulation thin-film wherein the
organic thin film deposition unit is arranged at a terminus of the
sequential connection of units.
[0028] Other features and aspects will be apparent from the
following detailed description, the drawings, and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] In the detailed description that follows, embodiments are
described as illustrations only since various changes and
modifications will become apparent to those skilled in the art from
the following detailed description. The use of the same reference
numbers in different figures indicates similar or identical
items.
[0030] FIG. 1A is a diagram that illustrates an example of an
inorganic thin film.
[0031] FIG. 1B to FIG. 1F are diagrams that illustrate an example
of ultra-flexible multilayer encapsulation thin-films including
inorganic thin films and organic thin films stacked
alternately.
[0032] FIG. 2 is a schematic diagram illustrating an example of a
spatial atomic layer deposition (ALD) in accordance with the
present disclosure.
[0033] FIG. 3 is a schematic diagram illustrating an example of a
device for growing an inorganic thin film of 5 nm and an organic
thin film in accordance with the present disclosure.
[0034] FIG. 4 is a schematic diagram illustrating an example of a
device for growing an aluminum oxide thin film of 0.11 nm and a
plasma polymer thin film in accordance the present disclosure.
[0035] FIG. 5 is a schematic diagram illustrating an example of an
apparatus for preparing a multilayer encapsulation thin-film in
accordance with the present disclosure.
[0036] FIG. 6 is a schematic diagram illustrating an example of an
apparatus for preparing a multilayer encapsulation thin-film in
accordance the present disclosure.
[0037] FIG. 7 is a schematic diagram illustrating an example of an
apparatus for preparing a multilayer encapsulation thin-film for
vertical deposition of films in accordance with the present
disclosure.
[0038] FIG. 8 is an electron micrograph of a cross section of an
example of a multilayer encapsulation thin-film formed for 20 dyads
in accordance with the present disclosure.
[0039] FIG. 9 is a graph showing a change in performance of an
example of an organic light emitting diode before and after a
multilayer encapsulation thin-film is formed in accordance with the
present disclosure.
[0040] FIG. 10 is a photograph of an example of a flexible organic
light emitting diode in which a multilayer encapsulation thin-film
is formed in accordance with the present disclosure.
[0041] FIG. 11 is a graph showing a change in water vapor
transmission rate (WVTR) depending on the number of dyads including
an inorganic thin film in an example of a multilayer encapsulation
thin-film in accordance with the present disclosure.
[0042] FIG. 12 is a graph comparing an inorganic thin film and an
8-dyad multilayer encapsulation thin-film in terms of a bending
property in accordance with the present disclosure.
[0043] FIG. 13 is a graph comparing an inorganic thin film and
multilayer encapsulation thin-films in terms of a bending property
in accordance with the present disclosure.
[0044] FIG. 14 is a graph showing an improvement in a bending
property at neutral planes of an 8-dyad multilayer encapsulation
thin-film and a 200-dyad multilayer encapsulation thin-film in
accordance with the present disclosure.
[0045] Throughout the drawings and the detailed description, unless
otherwise described or provided, the same drawing reference
numerals will be understood to refer to the same elements,
features, and structures. The drawings may not be to scale, and the
relative size, proportions, and depiction of elements in the
drawings may be exaggerated for clarity, illustration, and
convenience.
DETAILED DESCRIPTION
[0046] The following detailed description is provided to assist the
reader in gaining a comprehensive understanding of the methods,
apparatuses, and/or systems described herein. However, various
changes, modifications, and equivalents of the systems, apparatuses
and/or methods described herein will be apparent to one of ordinary
skill in the art. The progression of processing steps and/or
operations described is an example; however, the sequence of and/or
operations is not limited to that set forth herein and may be
changed as is known in the art, with the exception of steps and/or
operations necessarily occurring in a certain order. Also,
descriptions of functions and constructions that are well known to
one of ordinary skill in the art may be omitted for increased
clarity and conciseness.
[0047] The features described herein may be embodied in different
forms, and are not to be construed as being limited to the examples
described herein. Rather, the examples described herein have been
provided so that this disclosure will be thorough and complete, and
will convey the full scope of the disclosure to one of ordinary
skill in the art.
[0048] Hereinafter, embodiments of the present disclosure will be
described in detail with reference to the accompanying drawings so
that the present disclosure may be readily implemented by those
skilled in the art. However, it is to be noted that the present
disclosure is not limited to the embodiments but can be embodied in
various other ways. In drawings, parts irrelevant to the
description are omitted for the simplicity of explanation, and like
reference numerals denote like parts through the whole
document.
[0049] Through the whole document of the present disclosure, the
term "connected to" or "coupled to" that is used to designate a
connection or coupling of one element to another element includes
both a case that an element is "directly connected or coupled to"
another element and a case that an element is "electronically
connected or coupled to" another element via still another
element.
[0050] Through the whole document of the present disclosure, the
term "on" that is used to designate a position of one element with
respect to another element includes both a case that the one
element is adjacent to the another element and a case that any
other element exists between these two elements.
[0051] Through the whole document of the present disclosure, the
term "comprises or includes" and/or "comprising or including" used
in the document means that one or more other components, steps,
operation and/or existence or addition of elements are not excluded
in addition to the described components, steps, operation and/or
elements unless context dictates otherwise. Through the whole
document of the present disclosure, the term "about or
approximately" or "substantially" is intended to have meanings
close to numerical values or ranges specified with an allowable
error and intended to prevent accurate or absolute numerical values
disclosed for understanding of the present disclosure from being
illegally or unfairly used by any unconscionable third party.
Through the whole document of the present disclosure, the term
"step of" does not mean "step for".
[0052] Through the whole document of the present disclosure, the
term "combination of" included in Markush type description means
mixture or combination of one or more components, steps, operations
and/or elements selected from a group consisting of components,
steps, operation and/or elements described in Markush type and
thereby means that the disclosure includes one or more components,
steps, operations and/or elements selected from the Markush
group.
[0053] Through the whole document of the present disclosure, a
phrase in the form "A and/or B" means "A, B, or A and B".
[0054] Through the whole document of the present disclosure, the
term "plasma polymer" refers to a polymer formed through conversion
of a monomolecular organic material into highly reactive radicals
in plasma and radical-polymerization on a surface of a
substrate.
[0055] Hereinafter, illustrative descriptions and examples of the
present disclosure will be explained in detail with reference to
the accompanying drawings. However, the present disclosure may not
be limited to the illustrative descriptions, examples, and
drawings.
[0056] In view of the limitations described in the Description of
Related Art, the present disclosure provides an ultra-flexible
encapsulation thin-film and a method and apparatus for preparing
the ultra-flexible multilayer encapsulation thin-film.
[0057] However, limitations to be overcome by the present
disclosure are not limited to the above-described limitations.
Although not described herein, other limitations to be overcome by
the present disclosure can be clearly understood by those skilled
in the art from the following description.
[0058] In the multilayer encapsulation thin-film in accordance with
the present disclosure, inorganic materials are divided into
multiple layers, so that a thickness of each inorganic thin film
can be reduced. Therefore, fragility of the inorganic material can
be reduced and flexibility of the entire thin film can be improved.
Further, the organic thin films interposed between the inorganic
thin films may be more elastic than the inorganic thin films and
thus may offer an effect of improving a bending property of the
entire thin film.
[0059] Furthermore, even if water vapor or oxygen permeates through
cracks present in certain inorganic thin films, a path allowing
water vapor or oxygen can be lengthened. Therefore, it is possible
to greatly increase an effect of suppressing transmission of water
vapor.
[0060] The apparatus for preparing the ultra-flexible multilayer
encapsulation thin-film in accordance with the present disclosure
deposits the inorganic material and the organic material in the
same apparatus, and, thus, when an ultra-flexible encapsulation
thin-film is prepared, a processing time can be reduced.
[0061] The foregoing summary is illustrative only and is not
intended to be in any way limiting. In addition to the illustrative
aspects, embodiments, and features described above, further
aspects, embodiments, and features will become apparent by
reference to the drawings and the following detailed
description.
[0062] In one general aspect of the present disclosure, an
ultra-flexible multilayer encapsulation thin-film comprises an
inorganic thin film which contains a metal oxide and is formed on a
substrate, and an organic thin film which contains a polymer and is
formed on the inorganic thin film. The inorganic thin film and the
organic thin film are alternately stacked on each other in multiple
layers.
[0063] As depicted in FIG. 1, a multilayer encapsulation thin-film
in accordance with the present disclosure may be formed by stacking
an inorganic thin film 100 (e.g., Al.sub.2O.sub.3) and an organic
thin film 200 (e.g., plasma polymer [P.P]) in sequence, but may not
be limited thereto. By way of example, the number of dyads of the
multilayer encapsulation thin-film may be in a range of, but not
limited to, from about 2 dyads to about 200 dyads. By way of
example, the number of dyads of the multilayer encapsulation
thin-film may be in a range of, but not limited to, from about 2
dyads to about 200 dyads, from about 4 dyads to about 200 dyads,
from about 8 dyads to about 200 dyads, from about 10 dyads to about
200 dyads, from about 20 dyads to about 200 dyads, from about 50
dyads to about 200 dyads, from about 70 dyads to about 200 dyads,
from about 100 dyads to about 200 dyads, from about 130 dyads to
about 200 dyads, from about 150 dyads to about 200 dyads, from
about 180 dyads to about 200 dyads, from about 2 dyads to about 180
dyads, from about 4 dyads to about 180 dyads, from about 8 dyads to
about 180 dyads, from about 10 dyads to about 180 dyads, from about
20 dyads to about 180 dyads, from about 50 dyads to about 180
dyads, from about 70 dyads to about 180 dyads, from about 100 dyads
to about 180 dyads, from about 130 dyads to about 180 dyads, from
about 150 dyads to about 180 dyads, from about 2 dyads to about 150
dyads, from about 4 dyads to about 150 dyads, from about 8 dyads to
about 150 dyads, from about 10 dyads to about 150 dyads, from about
20 dyads to about 150 dyads, from about 50 dyads to about 150
dyads, from about 70 dyads to about 150 dyads, from about 100 dyads
to about 150 dyads, from about 130 dyads to about 150 dyads, from
about 2 dyads to about 130 dyads, from about 4 dyads to about 130
dyads, from about 8 dyads to about 130 dyads, from about 10 dyads
to about 130 dyads, from about 20 dyads to about 130 dyads, from
about 50 dyads to about 130 dyads, from about 70 dyads to about 130
dyads, from about 100 dyads to about 130 dyads, from about 2 dyads
to about 100 dyads, from about 4 dyads to about 100 dyads, from
about 8 dyads to about 100 dyads, from about 10 dyads to about 100
dyads, from about 20 dyads to about 100 dyads, from about 50 dyads
to about 100 dyads, from about 70 dyads to about 100 dyads, from
about 2 dyads to about 70 dyads, from about 4 dyads to about 70
dyads, from about 8 dyads to about 70 dyads, from about 10 dyads to
about 70 dyads, from about 20 dyads to about 70 dyads, from about
50 dyads to about 70 dyads, from about 2 dyads to about 50 dyads,
from about 4 dyads to about 50 dyads, from about 8 dyads to about
50 dyads, from about 10 dyads to about 50 dyads, from about 20
dyads to about 50 dyads, from about 2 dyads to about 20 dyads, from
about 4 dyads to about 20 dyads, from about 8 dyads to about 20
dyads, from about 10 dyads to about 20 dyads, from about 2 dyads to
about 10 dyads, from about 4 dyads to about 10 dyads, from about 8
dyads to about 10 dyads, from about 2 dyads to about 8 dyads, from
about 4 dyads to about 8 dyads, or from about 2 dyads to about 4
dyads. As the number of dyads of the multilayer encapsulation
thin-film is increased, a thickness of each inorganic thin film 100
is reduced and a path (e.g., illustrated by traversing arrows in
FIGS. 1A to 1C) allowing water vapor to permeate through cracks of
the inorganic thin film 100 is lengthened, and, thus, a property of
suppressing transmission of water vapor can be improved. Further,
flexibility can be improved due to elasticity of the organic thin
film 200.
[0064] In accordance with an illustrative description of the
present disclosure, the metal oxide may include, but may not be
limited to, a member selected from the group consisting of aluminum
oxide (Al.sub.2O.sub.3), zirconium oxide (ZrO.sub.2), zinc oxide,
silicon oxide (SiO.sub.2), silicon nitride (Si.sub.3N.sub.4),
silicon carbide (SiC), silicon oxynitride (Si.sub.2N.sub.2O),
silicon oxycarbide (SiOC), and combinations thereof.
[0065] In accordance with an illustrative description of the
present disclosure, a single layer of the inorganic thin film may
have a thickness in a range of, but not limited to, from about 0.1
nm to about 20 nm. By way of example, the inorganic thin film may
have a thickness in a range of, but not limited to, from about 0.1
nm to about 20 nm, from about 1 nm to about 20 nm, from about 2.5
nm to about 20 nm, from about 5 nm to about 20 nm, from about 10 nm
to about 20 nm, from about 0.1 nm to about 10 nm, from about 1 nm
to about 10 nm, from about 2.5 nm to about 10 nm, from about 5 nm
to about 10 nm, from about 0.1 nm to about 5 nm, from about 1 nm to
about 5 nm, from about 2.5 nm to about 5 nm, from about 0.1 nm to
about 2.5 nm, from about 1 nm to about 2.5 nm, or from about 0.1 nm
to about 1 nm.
[0066] In accordance with an illustrative description of the
present disclosure, the aggregate of all the layers of the
inorganic thin films in an encapsulation thin film may have a total
thickness in a range of, but not limited to, from about 0.1 nm to
about 20 nm. By way of example, the inorganic thin films may have a
combined thickness in a range of, but not limited to, from about
0.1 nm to about 20 nm, from about 1 nm to about 20 nm, from about
2.5 nm to about 20 nm, from about 5 nm to about 20 nm, from about
10 nm to about 20 nm, from about 0.1 nm to about 10 nm, from about
1 nm to about 10 nm, from about 2.5 nm to about 10 nm, from about 5
nm to about 10 nm, from about 0.1 nm to about 5 nm, from about 1 nm
to about 5 nm, from about 2.5 nm to about 5 nm, from about 0.1 nm
to about 2.5 nm, from about 1 nm to about 2.5 nm, or from about 0.1
nm to about 1 nm.
[0067] In accordance with an illustrative description of the
present disclosure, the polymer may include, but may not be limited
to, a member selected from the group consisting of a plasma
polymer, an acrylic polymer, and combinations thereof. By way of
example, the plasma polymer may include, but may not be limited to,
a member selected from the group consisting of hexamethyl
disiloxane (hereinafter, referred to as "HMDSO" in some cases),
1,4-epoxy-1,3-butadiene (hereinafter, referred to as "furan" in
some cases), hexane, and combinations thereof. By way of example,
the acrylic polymer may include, but may not be limited to, a
member selected from the group consisting of an acrylate, urethane
acrylate, a polyacrylate, a polyalkylacrylate, a polyacrylamide, an
ethylene-acrylic acid copolymer, and combinations thereof.
[0068] In accordance with an illustrative description of the
present disclosure, a single layer of the organic thin film 200 may
have a thickness in a range of, but not limited to, from about 20
nm to about 2 .mu.m. By way of example, the organic thin film may
have a thickness in a range of, but not limited to, from about 20
nm to about 2 .mu.m, from about 50 nm to about 2 .mu.m, from about
100 nm to about 2 .mu.m, from about 300 nm to about 2 .mu.m, from
about 500 nm to about 2 .mu.m, from about 700 nm to about 2 .mu.m,
from about 900 nm to about 2 .mu.m, from about 1 .mu.m to about 2
.mu.m, from about 20 nm to about 1 .mu.m, from about 50 nm to about
1 .mu.m, from about 100 nm to about 1 .mu.m, from about 300 nm to
about 1 .mu.m, from about 500 nm to about 1 .mu.m, from about 700
nm to about 1 .mu.m, from about 900 nm to about 1 .mu.m, from about
20 nm to about 900 nm, from about 50 nm to about 900 nm, from about
100 nm to about 900 nm, from about 300 nm to about 900 nm, from
about 500 nm to about 900 nm, from about 700 nm to about 900 nm,
from about 20 nm to about 700 nm, from about 50 nm to about 700 nm,
from about 100 nm to about 700 nm, from about 300 nm to about 700
nm, from about 500 nm to about 700 nm, from about 20 nm to about
500 nm, from about 50 nm to about 500 nm, from about 100 nm to
about 500 nm, from about 300 nm to about 500 nm, from about 20 nm
to about 300 nm, from about 50 nm to about 300 nm, from about 100
nm to about 300 nm, from about 20 nm to about 100 nm, from about 50
nm to about 100 nm, or from about 20 nm to about 50 nm.
[0069] If the multilayer encapsulation thin-film in accordance with
the present disclosure is positioned at a neutral plane where a
tensile force and a compressive force can be counterbalanced by
each other, the probability of appearance of cracks due to bending
may decrease, but the present disclosure may not be limited
thereto. By way of example, if the same material is used for upper
and lower parts of a multilayer thin film, the multilayer
encapsulation thin-film can be positioned at the neutral plane, but
may not be limited thereto. Theoretically, if upper and lower parts
are completely symmetric, a tensile force and/or a compressive
force are not applied to a neutral plane. Thus, appearance of
cracks can also be suppressed. However, in a practical process,
complete symmetry cannot be achieved. Thus, a tensile force and/or
a compressive force to a certain extent may be generated, but the
present disclosure may not be limited thereto.
[0070] In another general aspect of the present disclosure, a
preparing method of an ultra-flexible multilayer encapsulation
thin-film comprises forming an inorganic thin film containing a
metal oxide on a substrate, and forming an organic thin film
containing a polymer on the inorganic thin film. The forming the
inorganic thin film on the substrate and the forming the organic
thin film containing the polymer on the inorganic thin film are
alternately carried out, so that the inorganic thin film and the
organic thin film are alternately stacked on each other. All of the
descriptions regarding the previously described general aspect of
the present disclosure can be applied to the ultra-flexible
multilayer encapsulation thin-film in accordance with the present
general aspect.
[0071] In accordance with an illustrative description of the
present disclosure, the forming of the inorganic thin film may be
carried out by atomic layer deposition (ALD). If the inorganic thin
film is formed by atomic layer deposition, an inorganic thin film
having a small thickness of, but not limited to, about 20 nm or
less may be formed. By way of example, the inorganic thin film may
have a thickness of, but not limited to, about 20 nm or less, about
18 nm or less, about 16 nm or less, about 14 nm or less, about 12
nm or less, about 10 nm or less, about 8 nm or less, about 6 nm or
less, about 4 nm or less, about 2 nm or less, about 1 nm or less,
or about 0.5 nm or less.
[0072] In accordance with the present disclosure, the forming of
the organic thin film may be carried out by chemical vapor
deposition or atomic layer deposition. By way of example, if the
organic thin film contains a plasma polymer, the organic thin film
may be formed through conversion of an organic monomer into
radicals in plasma and radical-polymerization, but the present
disclosure may not be limited thereto. A monomer used for forming
the plasma polymer is not specifically limited. Any organic monomer
may be used to deposit the plasma polymer, but the present
disclosure may not be limited thereto. By way of example, the
monomer may include, but may not be limited to, a member selected
from the group consisting of HMDSO (hexamethyl disiloxane), furan
(1,4-epoxy-1,3-butadiene), hexane, and combinations thereof. By way
of example, if the organic thin film contains an acrylic polymer,
the organic thin film may be formed through coating of a monomer
and then UV-curing, but the present disclosure may not be limited
thereto. By way of example, the acrylic polymer may include, but
may not be limited to, a member selected from the group consisting
of an acrylate, urethane acrylate, a polyacrylate, a
polyalkylacrylate, a polyacrylamide, an ethylene-acrylic acid
copolymer, and combinations thereof. A single layer of the organic
thin film in accordance with the present disclosure may have a
thickness in a range of, but not limited to, from about 20 nm to
about 2 .mu.m depending on a coating thickness of the monomer
and/or an intensity of UV rays.
[0073] Deposition of the inorganic thin film and/or the organic
thin film in accordance with the present disclosure may be carried
out at a temperature in a range of, but not limited to, from room
temperature (about 20.degree. C.) to about 120.degree. C. By way of
example, deposition of the inorganic thin film and/or the organic
thin film may be carried out at a temperature in a range of, but
not limited to, from room temperature to about 120.degree. C., from
about 30.degree. C. to about 120.degree. C., from about 45.degree.
C. to about 120.degree. C., from about 60.degree. C. to about
120.degree. C., from about 75.degree. C. to about 120.degree. C.,
from about 90.degree. C. to about 120.degree. C., from about
105.degree. C. to about 120.degree. C., from room temperature to
about 105.degree. C., from about 30.degree. C. to about 105.degree.
C., from about 45.degree. C. to about 105.degree. C., from about
60.degree. C. to about 105.degree. C., from about 75.degree. C. to
about 105.degree. C., from about 90.degree. C. to about 105.degree.
C., from room temperature to about 90.degree. C., from about
30.degree. C. to about 90.degree. C., from about 45.degree. C. to
about 90.degree. C., from about 60.degree. C. to about 90.degree.
C., from about 75.degree. C. to about 90.degree. C., from room
temperature to about 75.degree. C., from about 30.degree. C. to
about 75.degree. C., from about 45.degree. C. to about 75.degree.
C., from about 60.degree. C. to about 75.degree. C., from room
temperature to about 60.degree. C., from about 30.degree. C. to
about 60.degree. C., from about 45.degree. C. to about 60.degree.
C., from room temperature to about 45.degree. C., from about
30.degree. C. to about 45.degree. C., or from room temperature to
about 30.degree. C.
[0074] In yet another general aspect of the present disclosure, an
apparatus for producing an ultra-flexible multilayer encapsulation
thin-film comprises a substrate loading unit on which a substrate
is loaded, an inorganic thin film deposition unit to deposit an
inorganic thin film on the substrate, and an organic thin film
deposition unit to deposit an organic thin film on the inorganic
thin film. The inorganic thin film deposition unit and the organic
thin film deposition unit are sequentially connected to each other,
and the substrate loading unit is alternately moved to the
inorganic thin film deposition unit and the organic thin film
deposition unit, so that the inorganic thin film and the organic
thin film are alternately deposited on each other on the
substrate.
[0075] The inorganic thin film in accordance with the present
disclosure is deposited on a substrate by ALD. In order to deposit
the inorganic thin film at a high speed, spatial atomic layer
deposition (spatial ALD) may be employed instead of temporal atomic
layer deposition (temporal ALD) typically used. As depicted in FIG.
2, spatial ALD refers to a method of spatially arranging raw
material modules for atomic layers on a moving substrate. A
processing time of the spatial ALD may be much shorter than that of
the temporal ALD in which the raw materials are repeatedly injected
and discharged for a short time. By way of example, if a multilayer
encapsulation thin-film including the inorganic thin film having a
thickness of about 5 nm is prepared using a spatial atomic layer
deposition device, a device schematically illustrated in FIG. 3 may
be used. A plasma polymer module may grow a plasma polymer to a
desired thickness in a single module depending on a design of the
device.
[0076] As depicted in FIG. 4, the number of modules required for
stacking an aluminum oxide thin film having a thickness of about
0.11 nm (for one cycle) and a plasma polymer thin film in sequence
in accordance with an example of the present disclosure can be
remarkably reduced, and, thus, a process device can be simplified.
Even with such a simplified process device, a multilayer
encapsulation thin-film having high flexibility and also satisfying
a water vapor transmission rate (WVTR) condition of an organic
light emitting diode can be prepared within a short time.
[0077] As depicted in FIG. 5, the organic thin film deposition unit
in accordance with the present disclosure may include, but may not
be limited to, UV curing units arranged on both sides of a monomer
injection unit.
[0078] In the apparatus for producing a multilayer encapsulation
thin-film in accordance with the present disclosure, the inorganic
thin film deposition unit and the organic thin film deposition unit
may be alternately arranged as depicted in FIG. 5, or the organic
thin film deposition unit may be positioned at first or at last as
depicted in FIG. 6. The inorganic thin film deposition unit and the
organic thin film deposition unit may be operated in separate
spaces within the same apparatus, but the present disclosure may
not be limited thereto.
[0079] If the multilayer encapsulation thin-film in accordance with
the present disclosure is formed to have a large area, the
multilayer encapsulation thin-film may be vertically formed as
depicted in FIG. 7.
[0080] Hereinafter, examples of the present disclosure will be
explained in detail. However, the present disclosure may not be
limited thereto.
EXAMPLE
[0081] In order to prepare a multilayer encapsulation thin-film, an
aluminum oxide thin film as an inorganic material was deposited by
atomic layer deposition, and a polymer thin film as an organic
material was deposited using a gas-phase radical polymerization
reactor using plasma. In order to prepare atomic layer deposition
of the aluminum oxide thin film, trimethyl aluminum (TMA) was used
as a raw material of aluminum and water was used as an oxidizer.
The atomic layer deposition of the aluminum oxide thin film was
carried out at about 80.degree. C. The aluminum oxide thin film
could grow to a thickness of about 0.11 nm during one reaction
cycle.
[0082] In order to grow the plasma polymer, HMDSO (hexamethyl
disiloxane), furan (1,4-epoxy-1,3-butadiene), or hexane was used as
an organic monomer. A source material was supplied using an argon
(Ar) carrier gas into plasma of about 50 W, and radicals of the
source material generated within the plasma were
radical-polymerized on a surface of a substrate, so that a polymer
was formed. The formed plasma polymer was transparent and deposited
at a speed of about 50 nm per minute.
[0083] FIG. 8 provides an electron micrograph of the formed
multilayer encapsulation thin-film. FIG. 8 is an electron
micrograph illustrating a structure in which an aluminum oxide
having a thickness of about 1 nm and a plasma polymer having a
thickness of about 20 nm are stacked for 20 dyads. It was confirmed
that even after a multilayer encapsulation thin-film is formed on
an organic light emitting diode, there is no change in performance
of the organic light emitting diode. As shown in FIG. 9, an organic
light emitting diode including the multilayer encapsulation
thin-film was equivalent to or superior to an organic light
emitting diode before the multilayer encapsulation thin-film was
formed, in terms of luminance, current density, and current
efficiency. FIG. 10 is a photograph of a highly flexible organic
light emitting diode including the multilayer encapsulation
thin-film. It was confirmed that the organic light emitting diode
including the multilayer encapsulation thin-film had a high
flexibility.
[0084] A water vapor transmission rate of the multilayer
encapsulation thin-film mainly depends on a property of the
inorganic thin film. An effect of suppressing transmission of water
vapor of the multilayer encapsulation thin-film can be seen from a
water vapor transmission rate (hereinafter, referred to as "WVTR)
shown in FIG. 11. The WVTR could be obtained by measuring a time
for which calcium having a certain electrical conductance is
oxidized with water vapor transmitted through the multilayer
encapsulation thin-film and turns to a calcium oxide without an
electrical conductance.
Evaluation of Bending Property of Thin Film
[0085] FIG. 12 shows a result of an experiment using a calcium test
before and after a bending test carried out 10,000 cycles on a
single aluminum oxide thin film having a thickness of about 20 nm
and an 8-dyad multilayer encapsulation thin-film with a bending
radius of about 3 cm, about 2 cm, about 1 cm, and about 0.5 cm. It
took about 18 hours and about 25 hours until calcium was completely
oxidized in the single aluminum oxide thin film and in the 8-dyad
multilayer encapsulation thin-film, respectively, before the
bending test ("as prepared"). As a time increased, a property of
suppressing transmission of water vapor was improved. Accordingly,
as a time increased, the WVTR was reduced. In the bending test of
10,000 cycles with a bending radius of about 3 cm, it took about 14
hours until calcium was completely reduced in the single aluminum
oxide thin film. However, in the multilayer encapsulation
thin-film, an amount of calcium reduced was relatively very small.
In the bending test with a smaller bending radius, a time tended to
be remarkably reduced in the single aluminum oxide thin film, but
there was almost no change in time for the multilayer encapsulation
thin-films. Therefore, it was confirmed that even when the bending
test was carried out 10,000 cycles with a bending radius of about 1
cm, there was almost no change in the property of suppressing
transmission of water vapor. However, when the bending test was
carried out with a bending radius of about 0.5 cm, both of the
single aluminum oxide thin film and the multilayer encapsulation
thin-film completely lost the property of suppressing transmission
of water vapor. As shown in FIG. 13, in the case of 20-dyad and
200-dyad multilayer encapsulation thin-films, even when the bending
test was carried out 10,000 cycles with a bending radius of about
0.5 cm, a water vapor transmission reduction rate was about 20%.
Therefore, it could be seen that they still had the property of
suppressing transmission of water vapor.
[0086] FIG. 14 is a graph showing a bending property at neutral
planes of an 8-dyad multilayer encapsulation thin-film and a
200-dyad multilayer encapsulation thin-film. The same material
(polyethylene naphthalate [PEN]) was used for upper and lower parts
of a multilayer thin film, so that a multilayer encapsulation
thin-film can be positioned at a neutral plane. As shown in FIG.
14, when the multilayer encapsulation thin-film was positioned at a
neutral plane, it was improved in a bending property as compared
with a multilayer encapsulation thin-film which was not. This may
be because a multilayer encapsulation thin-film which is positioned
at a neutral plane is not applied with a tensile force and/or a
compressive force as compared with multilayer encapsulation
thin-film which is not, and, thus, appearance of cracks can be
suppressed.
[0087] While this disclosure includes specific examples, it will be
apparent to one of ordinary skill in the art that various changes
in form and details may be made in these examples without departing
from the spirit and scope of the claims and their equivalents. The
examples described herein are to be considered in a descriptive
sense only, and not for purposes of limitation. Descriptions of
features or aspects in each example are to be considered as being
applicable to similar features or aspects in other examples.
Suitable results may be achieved if the described techniques are
performed in a different order, and/or if components in a described
system, architecture, device, or circuit are combined in a
different manner and/or replaced or supplemented by other
components or their equivalents. Therefore, the scope of the
disclosure is defined not by the detailed description, but by the
claims and their equivalents, and all variations within the scope
of the claims and their equivalents are to be construed as being
included in the disclosure.
* * * * *