U.S. patent application number 15/668643 was filed with the patent office on 2017-11-16 for inkjet printhead and apparatus and method for manufacturing organic luminescence display using the inkjet printhead.
The applicant listed for this patent is Samsung Display Co., Ltd.. Invention is credited to Jin Goo Kang.
Application Number | 20170331038 15/668643 |
Document ID | / |
Family ID | 50881225 |
Filed Date | 2017-11-16 |
United States Patent
Application |
20170331038 |
Kind Code |
A1 |
Kang; Jin Goo |
November 16, 2017 |
INKJET PRINTHEAD AND APPARATUS AND METHOD FOR MANUFACTURING ORGANIC
LUMINESCENCE DISPLAY USING THE INKJET PRINTHEAD
Abstract
An inkjet printhead, and an apparatus and method for
manufacturing an organic luminescence display using the inkjet
printhead. An apparatus for manufacturing an organic luminescence
display including an inkjet printhead placeable over a substrate
and including a plurality of nozzles; and a moving unit configured
to move at least one of the inkjet printhead or the substrate
relative to the other, and the plurality of nozzles includes one or
more ink ejecting nozzles ejecting an organic light-emitting ink;
and one or more solvent ejecting nozzles ejecting a first
solvent.
Inventors: |
Kang; Jin Goo; (Yongin-si,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Samsung Display Co., Ltd. |
Yongin-si |
|
KR |
|
|
Family ID: |
50881225 |
Appl. No.: |
15/668643 |
Filed: |
August 3, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13907778 |
May 31, 2013 |
9761801 |
|
|
15668643 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 51/0005 20130101;
H01L 51/56 20130101; H05B 33/10 20130101; B41J 2/2114 20130101 |
International
Class: |
H01L 51/00 20060101
H01L051/00; B41J 2/21 20060101 B41J002/21; H05B 33/10 20060101
H05B033/10 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 10, 2012 |
KR |
10-2012-0142802 |
Claims
1. An apparatus for manufacturing an organic luminescence display,
the apparatus comprising: an inkjet printhead placeable over a
substrate and comprising a plurality of nozzles; and a moving unit
configured to move at least one of the inkjet printhead or the
substrate relative to the other, wherein the plurality of nozzles
comprises: one or more ink ejecting nozzles ejecting an organic
light-emitting ink; and one or more solvent ejecting nozzles
ejecting a first solvent.
2. The apparatus of claim 1, wherein the nozzles are arranged in a
row in a first direction parallel to a surface of the substrate,
and the at least one of the inkjet printhead or the substrate moves
in a second direction perpendicular to the first direction and
parallel to the surface of the substrate.
3. The apparatus of claim 2, wherein the one or more solvent
ejecting nozzles are located at one or more ends of the plurality
of nozzles.
4. The apparatus of claim 3, wherein the one or more solvent
ejecting nozzles comprise solvent ejecting nozzles located at both
ends of the plurality of nozzles.
5. The apparatus of claim 2, wherein the one or more ink ejecting
nozzles and the one or more solvent ejecting nozzle are arranged
alternately.
6. The apparatus of claim 1, wherein the organic light-emitting ink
comprises an organic light-emitting material, and a second solvent
having a same composition as the first solvent.
7. The apparatus of claim 1, wherein the substrate includes a
display region to display images, and a non-display region to not
display images, and the one or more solvent ejecting nozzles eject
the first solvent onto at least a part of the non-display
region.
8. The apparatus of claim 7, wherein the non-display region
includes one or more dummy patterns located around the display
region, and the one or more solvent ejecting nozzles eject the
first solvent onto the one or more dummy patterns.
9. The apparatus of claim 7, wherein the one or more ink ejecting
nozzles eject the organic light-emitting ink onto at least a part
of the non-display region adjacent to the display region.
10. An inkjet printhead comprising: a plurality of nozzles arranged
in a row in a direction; and a head holder supporting the nozzles,
wherein the plurality of nozzles comprises: one or more solvent
ejecting nozzles ejecting a first solvent; and one or more ink
ejecting nozzles ejecting an organic light-emitting ink comprising
an organic light-emitting material and a second solvent having a
same composition as the first solvent.
11. The inkjet printhead of claim 10, wherein the one or more
solvent ejecting nozzles comprise solvent ejecting nozzles located
at both ends of the plurality of nozzles.
12. The inkjet printhead of claim 10, wherein the one or more ink
ejecting nozzles and the one or more solvent ejecting nozzles are
arranged alternately.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. patent application
Ser. No. 13/907,778, filed May 31, 2013, which claims priority to
and the benefit of Korean Patent Application No. 10-2012-0142802,
filed on Dec. 10, 2012, the entire contents of both of which are
incorporated herein by reference.
BACKGROUND
1. Field
[0002] Aspects of embodiments of the present invention relate to an
inkjet printhead and an apparatus and method for manufacturing an
organic luminescence display using the inkjet printhead.
2. Description of the Related Art
[0003] Displays, which display various information on a screen, are
core technology of the information and telecommunication age and
are developing into thinner, lighter, portable, and
high-performance displays. Accordingly, flat panel displays (such
as organic luminescence displays) which can overcome disadvantages
(i.e. weight and volume) of cathode ray tubes (CRTs) are attracting
a lot of attention. An organic luminescence display is a
self-emitting device that uses a thin organic light-emitting layer
between electrodes. The organic luminescence display can be made as
thin as paper. Organic luminescence displays can be classified into
small-molecule organic luminescence displays and polymer organic
luminescence displays according to the material of an organic
light-emitting layer that generates light. Generally, an organic
light-emitting layer of a small-molecule organic luminescence
display is formed as a thin film by vacuum deposition, and an
organic light-emitting layer of a polymer organic luminescence
display is formed as a thin film using a solution coating method
such as spin coating or inkjet printing.
[0004] When an organic light-emitting layer is formed by inkjet
printing, organic light-emitting ink, which includes an organic
light-emitting material and a solvent, is ejected from an inkjet
printhead onto one or more pixels on a substrate in a display
region, and then the ejected organic light-emitting ink is dried
into the organic light-emitting layer. Here, when the organic
light-emitting ink dries, it means that the solvent contained in
the organic light-emitting ink evaporates. Typically, the solvent
is highly volatile. Therefore, the solvent may be volatilized
shortly after the organic light-emitting ink is ejected, thereby
drying the organic light-emitting ink. Here, the concentration of
molecules of the evaporating solvent (hereinafter, referred to as
the concentration of evaporating solvent molecules) may be high in
the center of a region to which the organic light-emitting ink was
ejected and may be low at an edge of the region to which the
organic light-emitting ink was ejected, that is, at a boundary
between the region to which the organic light-emitting ink was
ejected and a region to which the organic light-emitting ink was
not ejected. This non-uniformity in the concentration gradient of
the evaporating solvent molecules on the substrate may induce the
evaporating solvent molecules to diffuse from the center of the
region to which the organic light-emitting ink was ejected to the
edge of the region to which the organic light-emitting ink was
ejected. In addition, the edge of the region to which the organic
light-emitting ink was ejected may dry relatively faster than the
center of the region to which the organic light-emitting ink was
ejected. Therefore, an organic light-emitting layer of a pixel
located at the edge of the region to which the organic
light-emitting ink was ejected may be concentrated toward the
outside of the region. That is, the organic light-emitting layer of
the pixel at the edge of the region to which the organic
light-emitting ink was ejected may have a non-uniform thickness.
The non-uniform thickness directly affects the display quality of
the organic luminescence display.
SUMMARY
[0005] According to an aspect of embodiments of the present
invention, an apparatus for manufacturing an organic luminescence
display may eject a solvent around a region to which organic
light-emitting ink including an organic light-emitting material and
a solvent is ejected, such that the ejected organic light-emitting
ink may be dried under a uniform concentration of evaporating
solvent molecules.
[0006] According to another aspect of embodiments of the present
invention, a method of manufacturing an organic luminescence
display is provided, in which a solvent is ejected around a region
to which organic light-emitting ink including an organic
light-emitting material and a solvent is ejected, such that the
ejected organic light-emitting ink may be dried under a uniform
concentration of evaporating solvent molecules.
[0007] According to another aspect of embodiments of the present
invention, an inkjet printhead used to manufacture an organic
luminescence display is configured to eject a solvent around a
region to which organic light-emitting ink including an organic
light-emitting material and a solvent is ejected, such that the
ejected organic light-emitting ink may be dried under a uniform
concentration of evaporating solvent molecules.
[0008] However, aspects of embodiments of the present invention are
not limited to those set forth herein. The above and other aspects
of the present invention will become more apparent to one of
ordinary skill in the art to which the present invention pertains
by referencing the description of some embodiments of the present
invention, as set forth below.
[0009] According to an embodiment of the present invention, an
apparatus for manufacturing an organic luminescence display
includes: an inkjet printhead placeable over a substrate and
including a plurality of nozzles; and a moving unit configured to
move at least one of the inkjet printhead or the substrate relative
to the other, and the plurality of nozzles includes one or more ink
ejecting nozzles ejecting an organic light-emitting ink; and one or
more solvent ejecting nozzles ejecting a first solvent.
[0010] According to another embodiment of the present invention, a
method of manufacturing an organic luminescence display includes:
ejecting a mixture of an organic light-emitting material and a
solvent onto one or more pixels arranged on a substrate and
ejecting the solvent around the one or more pixels; and drying the
mixture and the solvent.
[0011] According to another embodiment of the present invention, a
method of manufacturing an organic luminescence display includes:
first ejecting a first organic light-emitting ink onto a first
pixel region of a substrate, and first ejecting a first solvent
around the first pixel region; and first drying the first organic
light-emitting ink and the first solvent.
[0012] According to another embodiment of the present invention, an
inkjet printhead includes: a plurality of nozzles arranged in a row
in a direction; and a head holder supporting the nozzles, and the
plurality of nozzles include one or more solvent ejecting nozzles
ejecting a first solvent; and one or more ink ejecting nozzles
ejecting an organic light-emitting ink including an organic
light-emitting material and a second solvent having a same
composition as the first solvent.
[0013] Embodiments of the present invention may provide an organic
light-emitting layer having a uniform or substantially uniform
thickness.
[0014] In addition, embodiments of the present invention for
manufacturing an organic luminescence display may save
manufacturing costs by using a solvent that is relatively less
costly than the organic light-emitting ink.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The above and other aspects and principles of the present
invention will become more apparent by describing in further detail
some exemplary embodiments thereof with reference to the attached
drawings, in which:
[0016] FIG. 1 is a perspective view of an organic luminescence
display manufactured using an apparatus and method for
manufacturing an organic luminescence display according to
embodiments of the present invention;
[0017] FIG. 2 is a perspective view illustrating an apparatus and
method for manufacturing an organic luminescence display according
to an embodiment of the present invention;
[0018] FIG. 3 is a partial cross-sectional view of the organic
luminescence display of FIG. 1, taken along the line III-III';
[0019] FIG. 4 is a partial cross-sectional view of the organic
luminescence display of FIG. 1, taken along the line IV-IV';
[0020] FIG. 5 is a perspective view illustrating an apparatus and
method for manufacturing an organic luminescence display according
to another embodiment of the present invention;
[0021] FIGS. 6 through 9 are plan views illustrating a method of
manufacturing an organic luminescence display according to another
embodiment of the present invention; and
[0022] FIGS. 10 and 11 are plan views illustrating methods of
manufacturing an organic luminescence display according to other
embodiments of the present invention.
DETAILED DESCRIPTION
[0023] The present invention is described more fully hereinafter
with reference to the accompanying drawings, in which some
exemplary embodiments of the invention are shown. However, as those
skilled in the art would realize, the described embodiments may be
modified in various different ways, all without departing from the
spirit or scope of the present invention. Accordingly, the drawings
and description are to be regarded as illustrative in nature and
not restrictive. Like reference numbers indicate like components
throughout the specification.
[0024] The term "on" that is used to designate that an element is
on another element or located on a different layer or a layer
includes both a case where an element is located directly on
another element or a layer and a case where an element is located
on another element via another layer or still another element. In
the description of the present invention, like reference numbers
indicate like components throughout the specification and
figures.
[0025] Although the terms "first, second, and so forth" may be used
herein to describe various constituent elements, such constituent
elements are not limited by the terms. The terms are used only to
differentiate a constituent element from other constituent
elements. Accordingly, in the following description, a first
constituent element may be a second constituent element.
[0026] Hereinafter, some embodiments of the present invention will
be described with reference to the attached drawings.
[0027] FIG. 1 is a perspective view of an organic luminescence
display manufactured using an apparatus and method for
manufacturing an organic luminescence display according to
embodiments of the present invention. FIG. 2 is a perspective view
illustrating an apparatus and method for manufacturing an organic
luminescence display according to an embodiment of the present
invention. FIG. 3 is a partial cross-sectional view of the organic
luminescence display of FIG. 1, taken along the line III-III'. FIG.
4 is a partial cross-sectional view of the organic luminescence
display of FIG. 1, taken along the line IV-IV'.
[0028] In the description below, apparatuses and methods for
manufacturing an organic luminescence display may include various
apparatuses and methods using an inkjet printing method. In
addition to the apparatuses and methods using the inkjet printing
method, an apparatus and method for coating a liquid or semi-solid
organic light-emitting material on a substrate 200 may be included
in the apparatuses and methods for manufacturing an organic
luminescence display according to embodiments of the present
invention.
[0029] An apparatus for manufacturing an organic luminescence
display according to an embodiment of the present invention will
now be described with reference to FIGS. 1 through 4. Referring to
FIGS. 1 through 4, the apparatus for manufacturing an organic
luminescence display includes an inkjet printhead 100 and a moving
unit 900.
[0030] The inkjet printhead 100 may be placed over the substrate
200. In one embodiment, the substrate 200 may be a unit display
substrate 200 or may be a mother substrate before being cut and
split into a plurality of unit display substrates 200. In addition,
the substrate 200 may be a substrate without a structure or a
substrate having at least part of a structure formed thereon. The
structure formed on the substrate 200 may be a complete structure
or an incomplete structure. The substrate 200 may be a single
substrate 200 or may be a stack of multiple substrates 200.
[0031] The substrate 200 may be divided into a display region 700
and a non-display region. The display region 700 may be a region in
which images are displayed, and the non-display region may be a
region in which no images are displayed, that is, all regions of
the substrate 200 excluding the display region 700. A plurality of
pixels 710 may be located in the display region 700 of the
substrate 200. Each of the pixels 710 may have a cuboid or a
rectangular prismatic shape, for example. The pixels 710 may be
arranged in an n.times.m matrix form, where n and m are integers of
1 or more. In one embodiment, as shown in FIGS. 1 and 2, where a
row direction is an x-axis direction and a column direction is a
y-axis direction, the pixels 710 may be arranged in a 4.times.6
matrix form in the display region 700. However, the arrangement of
the pixels 710 shown in FIGS. 1 and 2 is merely one embodiment used
as an example for ease of description. In other embodiments, more
or less pixels 710 than that shown in FIGS. 1 and 2 may be arranged
on the substrate 200. In addition, the pixels 710 can be arranged
in various forms (e.g., a striped form and a PENTILE form), as well
as the matrix form. PENTILE is a registered trademark owned by
Samsung Display Co., Ltd.
[0032] A driver (not shown) may be formed in the non-display region
of the substrate 200. Patterned structures, such as the pixels 710,
do not usually exist in the non-display region, except for the
driver. However, as shown in FIGS. 1 and 2, a dummy region 800 may
be formed in a portion of the non-display region adjacent to the
display region 700, and one or more dummy patterns 810 may be
formed within the dummy region 800. The dummy patterns 810 may have
the same shape as the pixels 710 and may be formed on a side of the
pixels 710 as a whole to be arranged in the same form in which the
pixels 710 are arranged. In one embodiment, as shown in FIGS. 1 and
2, two columns of dummy patterns 810 may be formed at both ends of
the substrate 200, respectively, and the dummy patterns 810 may be
formed to have the same shape as the pixels 710. Furthermore, since
the dummy patterns 810 are arranged in the same form in which the
pixels 710 are arranged, all patterns (including the pixels 710 and
the dummy patterns 810) on the substrate 200 may be arranged in the
n.times.m matrix form. In one embodiment, as shown in FIGS. 1 and
2, all patterns may be arranged in a 4.times.8 matrix form, for
example. However, embodiments of the present invention are not
limited thereto.
[0033] A pixel defined layer 300 may be formed on the substrate
200. The pixel defined layer 300, as its name suggests, may define
regions in which the pixels 710 are formed within the display
region 700. In the embodiment of FIGS. 1 and 2, regions surrounded
by the pixel defined layer 300 may define the pixels 710. In
addition to what its name suggests, the pixel defined layer 300 may
define regions in which the dummy patterns 810 are formed within
the dummy region 800. That is, in the embodiment of FIGS. 1 and 2,
regions surrounded by the pixel defined layer 300 may define the
dummy patterns 810. The pixel defined layer 300 may be made of an
insulating material and may be formed by a mask patterning process,
such as a patterning process using a fine metal mask, for example.
In one embodiment, a surface of the pixel defined layer 300 may be
coated with a fluorine-containing material. In one embodiment, the
pixel defined layer 300 itself may contain fluorine. In one
embodiment, after the pixel defined layer 300 is formed, it may be
treated with fluorine plasma. The fluorine treatment of the pixel
defined layer 300 may reduce a surface energy of the pixel defined
layer 300, thereby preventing or substantially preventing adhesion
of foreign matter to a surface of the pixel defined layer 300.
[0034] An electrode 400 may be formed on a portion of the substrate
200 which corresponds to each of the pixels 710. The electrode 400
may cause an organic light-emitting layer 501 (which will be
described later) to emit light by applying a voltage to each of the
pixels 710. The electrode 400 may be formed to directly contact the
substrate 200, and each of the pixels 710 may be defined on the
electrode 400. That is, a region surrounded by the electrode 400
and the pixel defined layer 300 may be defined as each of the
pixels 710. In one embodiment, the electrode 400 may be a
transparent electrode and an anode. The electrode 400 may be formed
in a same manner as the pixel defined layer 300 is formed. However,
the electrode 400 may be formed before the pixel defined layer 300,
and different masks may be used to form the electrode 400 and the
pixel defined layer 300.
[0035] In one embodiment, the inkjet printhead 100 includes a head
holder 110 and a plurality of nozzles. The head holder 110 may
support the nozzles. The head holder 110, in one embodiment, may
extend in a first direction parallel to a surface of the substrate
200, may be parallel to a side of the substrate 200, and may be
separated from the substrate 200 by a distance (e.g., a
predetermined distance). The head holder 110 may be, but is not
limited to, cuboid-shaped or rectangular prismatic-shaped. The
nozzles may be installed on a surface of the head holder 110 which
faces the surface of the substrate 200. The area of the surface of
the head holder 110 which faces the surface of the substrate 200
may be smaller than the area of the surface of the substrate 200.
However, the present invention is not limited thereto, and the area
of the surface facing the surface of the substrate 200 may be equal
to or larger than the area of the surface of the substrate 200.
Although not shown in the drawings, the head holder 110 may be
connected to the moving unit 900 which moves the inkjet print head
100 and/or a control unit which controls a moving speed or
direction of the inkjet printhead 100.
[0036] The nozzles may be arranged in a row in the first direction
parallel to the surface of the substrate 200. Alternatively, the
nozzles may be arranged in multiple rows, that is, in a matrix
form. However, the present invention is not limited thereto, and
the nozzles can be arranged in various forms (such as the PENTILE
form) corresponding to the forms in which the pixels 710 are
arranged. In one embodiment, the nozzles may be arranged parallel
to the side of the substrate 200. In one embodiment, as shown in
FIG. 2, multiple nozzles (e.g., eight nozzles) may be arranged in a
row in the x-axis direction. In some cases, the nozzles may be
arranged obliquely to the side of the substrate 200. The nozzles
may be spaced at regular intervals. However, the present invention
is not limited thereto, and, in other embodiments, the nozzles may
be spaced at irregular intervals and arranged in a form
corresponding to a form in which the pixels 710 are arranged on the
substrate 200.
[0037] The moving unit 900 may move the inkjet printhead 100 or the
substrate 200. The moving unit 900 may be connected to the head
holder 110. In one embodiment, in a state in which the substrate
200 is fixed, the moving unit 900 may move the inkjet printhead 100
in a second direction perpendicular to the first direction in which
the nozzles are arranged and parallel to the surface of the
substrate 200. In one embodiment, in a state in which the substrate
200 is fixed, the moving unit 900 may move the inkjet printhead 100
in a y-axis direction or a direction opposite the y-axis direction.
In addition, the moving unit 900 may be connected to a substrate
support (not shown). In one embodiment, in a state in which the
inkjet printhead 100 is fixed, the moving unit 900 may move the
substrate 200 in the second direction perpendicular to the first
direction in which the nozzles are arranged and parallel to the
surface of the substrate 200. In one embodiment, in a state in
which the inkjet printhead 100 is fixed, the moving unit 900 may
move the substrate 200 in the y-axis direction or the direction
opposite the y-axis direction. In another embodiment, both the
inkjet printhead 100 and the substrate 200 may be moved relative to
each other.
[0038] The nozzles, in one embodiment, include one or more ink
ejecting nozzles 120 which eject organic light-emitting ink 500 and
one or more solvent ejecting nozzles 130 which eject a first
solvent 600. In FIG. 2, the ink ejecting nozzles 120 are shaded for
clarity, and the solvent ejecting nozzles 130 are not shaded.
[0039] The organic light-emitting ink 500 may be a material for
forming the organic light-emitting layer 501 and may include an
organic light-emitting material and a second solvent 610 (see FIG.
7). That is, as the organic light-emitting ink 500 dries on the
substrate 200, all of the second solvent 610 may evaporate,
resulting in the formation of the organic light-emitting layer 501.
The organic light-emitting material may be a red organic
light-emitting material, a green organic light-emitting material,
or a blue organic light-emitting material. When a voltage is
applied to the organic light-emitting material, the organic
light-emitting material may emit red, green or blue light. The
second solvent 610 is used to melt the organic light-emitting
material into a liquid state and may be a material that is highly
volatile and mixes well with the organic light-emitting material.
The second solvent 610 may have the same composition as the first
solvent 600. However, the present invention is not limited thereto.
The organic light-emitting ink 500 may include a dispersing agent
and/or a bonding agent in addition to the organic light-emitting
material and the second solvent 610.
[0040] The organic light-emitting ink 500 may include a red ink 510
including the red organic light-emitting material and the second
solvent 610, a green ink 520 including the green organic
light-emitting material and the second solvent 610, and a blue ink
530 including the blue organic light-emitting material and the
second solvent 610. When the second solvent 610 evaporates by the
drying of the red ink 510, the green ink 520 and the blue ink 530,
a red light-emitting layer 511, a green light-emitting layer 521,
and a blue light-emitting layer 531 may be formed,
respectively.
[0041] The ink ejecting nozzles 120 may include at least one of a
red ink ejecting nozzle 121 which ejects the red ink 510, a green
ink ejecting nozzle 122 which ejects the green ink 520, and a blue
ink ejecting nozzle 123 which ejects the blue ink 530. In one
embodiment, one set of the red ink ejecting nozzle 121, the green
ink ejecting nozzle 122 and the blue ink ejecting nozzle 123 may be
formed, and this set may be repeated. In the embodiment of FIG. 2,
for example, two sets of the red ink ejecting nozzle 121, the green
ink ejecting nozzle 122, and the blue ink ejecting nozzle 123 may
be arranged in a row. However, the present invention is not limited
thereto, and the red ink ejecting nozzle 121, the green ink
ejecting nozzle 122, and the blue ink ejecting nozzle 123 may be
arranged in various other orders and forms.
[0042] The first solvent 600 may be a material that can melt the
organic light-emitting material into a liquid state and may be a
material that is highly volatile and mixes well with the organic
light-emitting material. As described above, the first solvent 600
may have the same composition as the second solvent 610. However,
the present invention is not limited thereto. In one embodiment,
the first solvent 600 may be less volatile than the second solvent
610. The first solvent 600 may evaporate rapidly (e.g., within a
few seconds) after it is ejected. That is, a region to which the
first solvent 600 is ejected may be restored to its original state
after a certain period of time unless the region to which the first
solvent 600 is ejected absorbs the first solvent 600 or the first
solvent 600 causes a chemical reaction in the region to which the
first solvent 600 is ejected.
[0043] In one embodiment, the solvent ejecting nozzles 130 may
eject a highly volatile material other than the first solvent 600.
In this case, the material can be ejected to any region of the
substrate 200 as long as a region to which the material is ejected
can be restored to its original state after a certain period of
time. However, if the region to which the material is ejected
becomes denatured, the material may be ejected onto the non-display
region to not affect characteristics of an organic luminescence
display.
[0044] The solvent ejecting nozzles 130 may be located at one or
more ends of multiple nozzles arranged in a row in the first
direction. If the multiple nozzles are arranged in a row in the
first direction, an end may be a first nozzle or a last nozzle. In
one embodiment, the solvent ejecting nozzles 130 may be located at
both ends of the multiple nozzles. In another embodiment, the ink
ejecting nozzles 120 and the solvent ejecting nozzles 130 may be
arranged alternately, and the solvent ejecting nozzles 130 may be
located at both ends of the multiple nozzles.
[0045] The apparatus for manufacturing an organic luminescence
display according to one embodiment may eject the first solvent 600
around a region to which the organic light-emitting ink 500 is
ejected. In one embodiment, at the same time as when the ink
ejecting nozzles 120 eject the organic light-emitting ink 500 to
one or more of the pixels 710 on the substrate 200, the solvent
ejecting nozzles 130 may eject the first solvent 600 around the
pixels 710 to which the organic light-emitting ink 500 is ejected.
In another embodiment, the solvent ejecting nozzles 130 may eject
the first solvent 600 onto at least part of the non-display region.
In one embodiment, the solvent ejecting nozzles 130 may eject the
first solvent 600 onto the dummy region 800. The first solvent 600
ejected onto the dummy patterns 810 may fill the dummy patterns
810.
[0046] In one embodiment, the apparatus for manufacturing an
organic luminescence display may eject the organic light-emitting
material and the first solvent 600 onto the substrate 200 in the
form of a line by using a line printing method. In the embodiment
of FIG. 2, the nozzles arranged in a row in the x-axis direction
may move in the y-axis direction while ejecting the organic
light-emitting ink 500 and the first solvent 600 onto the display
region 700 and the dummy region 800 of the substrate 200,
respectively. In this case, the pixels 710 within the display
region 700 may be filled with the organic light-emitting ink 500,
and the dummy patterns 810 within the dummy region 800 may be
filled with the first solvent 600. In one embodiment, the organic
light-emitting ink 500 and the first solvent 600 may be ejected in
the form of continuous lines. In this case, the organic
light-emitting ink 500 and the first solvent 600 may be coated on
the pixels 710, the dummy patterns 810, respectively, and the pixel
defined layer 300 located on the movement path of the nozzles. If
the pixel defined layer 300 is treated with fluorine as described
above, the organic light-emitting ink 500 and the first solvent 600
may be pulled toward the pixels 710 and the dummy patterns 810,
respectively. The movement path of the nozzles may extend from an
end of the substrate 200 to another end which is opposite the end.
Therefore, the organic light-emitting ink 500 may be ejected onto
at least part of the non-display region adjacent to the display
region 700. The apparatus for manufacturing an organic luminescence
display may use a dot-printing method as well as the line-printing
method. In this case, the apparatus for manufacturing an organic
luminescence display may selectively eject the organic
light-emitting ink 500 and the first solvent 600 onto the pixels
710 and the dummy patterns 810, respectively.
[0047] In the apparatus for manufacturing an organic luminescence
display according to one embodiment, the organic light-emitting ink
500 ejected from the inkjet printhead 100 onto the pixels 710 of
the substrate 200 is dried under a uniform concentration of
evaporating solvent molecules due to the organic light-emitting ink
500 and/or the first solvent 600 around the pixels 710. As a
result, the organic light-emitting layer 501 having a uniform
thickness may be formed. This is described further below with
reference to FIGS. 3 and 4.
[0048] FIG. 3 is a cross-sectional view of the organic
light-emitting display in which the organic light-emitting ink 500
ejected onto the substrate 200 in an inkjet printing manner has
dried, taken along the line III-III' of FIG. 1. That is, FIG. 3 is
a cross-sectional view taken along the same direction as the
movement direction of the nozzles. First, the organic
light-emitting ink 500, i.e. the red ink 510, may be ejected onto
only a pixel 710 of FIG. 3 and may not be ejected onto the pixel
defined layer 300 adjacent the pixel 710 of FIG. 3 in the y-axis
direction or the direction opposite the y-axis direction. In this
case, an interface of the red light-emitting layer 511 formed in
the pixel 710 is defined as "an uncorrected interface B of the red
light-emitting layer 511." In one embodiment, the red ink 510 can
be ejected not only onto the pixel 710 of FIG. 3 but also onto the
pixel defined layer 300 adjacent the pixel 710 of FIG. 3 in the
y-axis direction or the direction opposite the y-axis direction. In
this case, an interface of the red light-emitting layer 511 formed
in the pixel 710 of FIG. 3 is defined as "a corrected interface A
of the red light-emitting layer 511." If the two interfaces are
compared, the uncorrected interface B of the red light-emitting
layer 511 may be uneven because the concentration of evaporating
solvent molecules around the pixel 710 of FIG. 3, in particular,
the concentration of evaporating solvent molecules in the direction
opposite the y-axis direction from the pixel 710 of FIG. 3 is lower
than the concentration of evaporating solvent molecules in the
pixel 710 of FIG. 3, and the red ink 510 adjacent the pixel 710 of
FIG. 3 in the direction opposite the y-axis direction dries
relatively faster. However, the corrected interface A of the red
light-emitting layer 511 may be even or relatively even because the
red ink 510 ejected onto the pixel defined layer 300 causes the
concentration of evaporating solvent molecules around the pixel 710
of FIG. 3 to be similar to the concentration of evaporating solvent
molecules in the pixel 710 of FIG. 3, and thus the red ink 510 is
dried under the uniform concentration of evaporating solvent
molecules across the pixel 710 of FIG. 3.
[0049] FIG. 4 is a cross-sectional view of the organic
light-emitting display in which the organic light-emitting ink 500
ejected onto the substrate 200 in an inkjet printing manner has
dried, taken along the line IV-IV' of FIG. 1. That is, FIG. 4 is a
cross-sectional view taken along a direction perpendicular to the
movement direction of the nozzles. First, the organic
light-emitting ink 500, i.e. the red ink 510, may be ejected onto
only a pixel 710 of FIG. 4 and may not be ejected onto a dummy
pattern adjacent from the pixel 710 of FIG. 4 in the direction
opposite the x-axis direction. In this case, an interface of the
red light-emitting layer 511 formed in the pixel 710 of FIG. 4 is
defined as "an uncorrected interface B' of the red light-emitting
layer 511." In one embodiment, the red ink 510 can be ejected not
only onto the pixel 710 of FIG. 4 but also onto the dummy pattern
adjacent from the pixel 710 of FIG. 4 in the direction opposite the
x-axis direction. In this case, an interface of the red
light-emitting layer 511 formed in the pixel 710 of FIG. 4 is
defined as "a corrected interface A' of the red light-emitting
layer 511." If the two interfaces are compared, the uncorrected
interface B' of the red light-emitting layer 511 may be uneven
because the concentration of evaporating solvent molecules around
the pixel 710 of FIG. 4, in particular, the concentration of
evaporating solvent molecules in the direction opposite the x-axis
direction from the pixel 710 of FIG. 4 is lower than the
concentration of evaporating solvent molecules in the pixel 710 of
FIG. 4, and the red ink 510 adjacent from the pixel 710 of FIG. 4
in the direction opposite the x-axis direction dries relatively
faster. However, the corrected interface A' of the red
light-emitting layer 511 may be even or relatively even because the
red ink 510 ejected onto the dummy pattern causes the concentration
of evaporating solvent molecules around the pixel 710 of FIG. 4 to
be similar to the concentration of evaporating solvent molecules in
the pixel 710 of FIG. 4, and thus the red ink 510 is dried under
the uniform concentration of evaporating solvent molecules across
the pixel 710 of FIG. 4.
[0050] In addition to the above-described effects, the apparatus
for manufacturing an organic luminescence display according to
embodiments of the present invention can save manufacturing costs
by using a solvent relatively less costly than the organic
light-emitting ink 500.
[0051] An apparatus for manufacturing an organic luminescence
display according to another embodiment of the present invention
will now be described with reference to FIG. 5. FIG. 5 is a
perspective view illustrating an apparatus and method for
manufacturing an organic luminescence display according to another
embodiment of the present invention. For simplicity, elements which
are the same as those of FIGS. 1 through 4 are indicated by like
reference numerals, and repeated description thereof will be
omitted.
[0052] In an inkjet printhead 101 of the apparatus for
manufacturing an organic luminescence display according to another
embodiment, one type of ink ejecting head is installed at a head
holder 111. In the embodiment of FIG. 5, the inkjet printhead 101
may include solvent ejecting nozzles 130 at both ends thereof and a
red ink ejecting nozzle 121 in the middle. While moving in a
reciprocating manner, the inkjet printhead 101 may eject red ink
510 to pixels 710 on a substrate 200 in a line printing or dot
printing manner. In another embodiment, the inkjet printhead 101
may be extended in a first direction, that is, in an x-axis
direction of FIG. 5 and may include a plurality of red ink ejecting
nozzles 121. In this case, a red light-emitting layer 511 may be
formed on the entire substrate 200 by one scanning of the inkjet
printhead 101 and drying.
[0053] Although not shown in FIG. 5, the apparatus for
manufacturing an organic luminescence display according to one
embodiment may additionally include an inkjet printhead 101 which
includes a green ink ejecting nozzle 122 and solvent ejecting
nozzles 130 and an inkjet printhead 101 which includes a blue ink
ejecting nozzle 123 and solvent ejecting nozzles 130. The inkjet
printheads 101 may individually eject organic light-emitting ink
500, that is, the red ink 510, green ink 520, and blue ink 530 onto
the substrate 200. In one embodiment, the inkjet printheads 101 may
be arranged in a stepped manner when seen in a plan view. Thus,
they may successively eject the red ink 510, the green ink 520, and
the blue ink 530.
[0054] A method of manufacturing an organic luminescence display
according to an embodiment of the present invention will now be
described with reference to FIGS. 1 through 4. For simplicity,
elements which are the same as those of the above-described
apparatus for manufacturing an organic luminescence display are
indicated by like reference numerals, and repeated description
thereof will be omitted.
[0055] Referring to FIGS. 1 and 2, the method of manufacturing an
organic luminescence display according to one embodiment includes
an operation of ejecting a mixture (i.e. organic light-emitting ink
500) of an organic light-emitting material and a second solvent 610
onto one or more pixels 710 arranged on a substrate 200 and
ejecting a first solvent 600 onto a region around each of the
pixels 710. Here, the region around each of the pixels 710 may
include not only other pixels 710 or dot patterns adjacent to the
corresponding pixel 710 but also a pixel defined layer 300 adjacent
to the corresponding pixel 710. In addition, the organic
light-emitting ink 500 as well as the first solvent 600 may be
ejected onto the region around each of the pixels 710. As described
above, the first solvent 600 and the second solvent 610 may have
the same composition. In addition, the ejecting operation may be
performed in a line printing or dot printing manner using the
inkjet printhead 100.
[0056] The first solvent 600 may be ejected in the form of a line
onto a non-display region adjacent to at least one boundary of a
display region 700. In one embodiment, the first solvent 600 may be
ejected in the form of lines onto a dummy region 800 adjacent to
both ends of the display region 700. In this case, the first
solvent 600 may be ejected not only onto one or more dummy patterns
formed adjacent to the display region 700 but also onto the pixel
defined layer 300 adjacent to the display region 700. In another
exemplary embodiment, the first solvent 600 may also be ejected
onto the non-display region adjacent to edges (e.g., all edges) of
the display region 700.
[0057] The method of manufacturing an organic luminescence display
according to one embodiment may include an operation of drying the
organic light-emitting ink 500 and the first solvent 600 after the
ejecting operation. In the drying operation, since the
concentration gradient of evaporating solvent molecules on the
substrate 200 is uniform, an organic light-emitting layer 501 may
be formed to a uniform thickness on the substrate 200,
particularly, on the display region 700. This has already been
described above with reference to FIGS. 3 and 4. In addition, since
all of the solvent ejected onto the region around each of the
pixels 710 evaporates, it does not affect an organic light-emitting
display.
[0058] FIGS. 6 through 9 are plan views illustrating a method of
manufacturing an organic luminescence display according to another
embodiment of the present invention. For simplicity, elements
substantially the same as those of FIGS. 1 through 4 are indicated
by like reference numerals, and thus repeated description thereof
will be omitted.
[0059] Referring to FIG. 6, the method of manufacturing an organic
luminescent display according to one embodiment may include a first
ejecting operation, a first drying operation, a second ejecting
operation, a second drying operation, a third ejecting operation,
and a third drying operation.
[0060] In the first ejecting operation, first organic
light-emitting ink may be ejected onto a first pixel region on a
substrate 200, and a first solvent 600 may be ejected onto a region
around the first pixel region. Here, the first pixel region may be
a region including pixels 710 in which a red light-emitting layer
511 is formed, and the first organic light-emitting ink may be red
ink 510. In addition, if the first organic light-emitting ink is
ejected in the form of a line by line printing, the region around
the first pixel region may be lines on both sides of the line of
the ejected first organic light-emitting ink. In the embodiment
shown in FIG. 6, the red ink 510 may be ejected in the form of a
line from an end of the substrate 200 to the other end of the
substrate 200, and the first solvent 600 may be ejected in the form
of lines on both sides of the ejected red ink 510. In one
embodiment, for example, a total of two lines of the red ink 510
and four lines of the first solvent 600 may be ejected.
[0061] In the first drying operation, the first organic
light-emitting ink and the first solvent 600 may be dried after the
first ejecting operation. The first organic light-emitting ink
(e.g., the red ink 510) may be dried into an organic light-emitting
layer 501 (e.g., the red light-emitting layer 511). In addition,
the first solvent 600 may evaporate as it dries, and, as a result,
all of the first solvent 600 may be removed. Since the red ink 510
is dried in a uniform drying atmosphere due to the presence of the
first solvent 600 on both sides of the red ink 510, it can be
formed into the red light-emitting layer 511 having a uniform
thickness.
[0062] Referring to FIG. 7, the second ejecting operation is
performed after the first drying operation. In the second ejecting
operation, second organic light-emitting ink different from the
first organic light-emitting ink may be ejected onto a second pixel
region adjacent to the first pixel region, and a second solvent 610
may be ejected onto a region around the second pixel region. Here,
the second pixel region may be a region including pixels 710 in
which a green light-emitting layer 521 is formed, and the second
organic light-emitting ink may be green ink 520. In addition, if
the second organic light-emitting ink is ejected in the form of a
line by line printing, the region around the second pixel region
may be lines on both sides of the line of the ejected second
organic light-emitting ink. In one embodiment, the green ink 520
may be ejected in the form of a line from an end of the substrate
200 to the other end of the substrate 200, and the second solvent
610 may be ejected in the form of lines on both sides of the
ejected green ink 520. In one embodiment, for example, two lines of
the green ink 520 and four lines of the second solvent 610 may be
ejected. Here, the first solvent 600 and the second solvent 610 may
have the same composition. In addition, when the second solvent 610
is ejected onto the region around the second pixel region, it may
be ejected onto the already dried first pixel region. That is, as
shown in FIG. 7, the second solvent 610 may be ejected onto the red
light-emitting layer 511 formed as a result of drying the red ink
510.
[0063] In the second drying operation, the second organic
light-emitting ink and the second solvent 610 may be dried after
the second ejecting operation. The second organic light-emitting
ink (e.g., the green ink 520) may be dried into an organic
light-emitting layer 501 (e.g., the green light-emitting layer
521). In addition, the second solvent 610 may evaporate as it
dries. As a result, all of the second solvent 610 may be removed.
In particular, all of the second solvent 610 ejected onto the red
light-emitting layer 511 may also be removed. Therefore, the red
light-emitting layer 511 may remain in the same state as after the
first drying operation. Since the green ink 520 is dried in a
uniform drying atmosphere due to the presence of the second solvent
610 on both sides of the green ink 520, it can be formed into the
green light-emitting layer 521 having a uniform thickness.
[0064] Referring to FIG. 8, the third ejecting operation is
performed after the second drying operation. In the third ejecting
operation, third organic light-emitting ink different from the
second organic light-emitting ink may be ejected onto a third pixel
region adjacent to the second pixel region, and a third solvent 620
may be ejected onto a region around the third pixel region. Here,
the third pixel region may be a region including pixels 710 in
which a blue light-emitting layer 531 is formed, and the third
organic light-emitting ink may be blue ink 530. In addition, if the
third organic light-emitting ink is ejected in the form of a line
by line printing, the region around the third pixel region may be
lines on both sides of the line of the ejected third organic
light-emitting ink. In one embodiment, the blue ink 530 may be
ejected in the form of a line from an end of the substrate 200 to
the other end of the substrate 200, and the third solvent 620 may
be ejected in the form of lines on both sides of the ejected blue
ink 530. In one embodiment, for example, two lines of the blue ink
530 and four lines of the third solvent 630 may be ejected. Here,
the third solvent 620 may have the same composition as the first
solvent 600 and the second solvent 610. In addition, when the third
solvent 620 is ejected onto the region around the third pixel
region, it may be ejected onto the already dried second pixel
region. That is, as shown in FIG. 8, the third solvent 620 may be
ejected onto the red light-emitting layer 511 and the green
light-emitting layer 521 formed as a result of drying the red ink
510 and the green ink 520.
[0065] In the third drying operation, the third organic
light-emitting ink and the third solvent 620 may be dried after the
third ejecting operation. The third organic light-emitting ink
(e.g., the blue ink 530) may be dried into an organic
light-emitting layer 501 (e.g., the blue light-emitting layer 531).
In addition, the third solvent 620 may evaporate as it dries. As a
result, all of the third solvent 620 may be removed. In particular,
all of the third solvent 620 ejected onto the red light-emitting
layer 511 and the green light-emitting layer 521 may also be
removed. Therefore, the red light-emitting layer 511 and the green
light-emitting layer 521 may remain in the same state as after the
first drying operation and the second drying operation. Since the
blue ink 530 is dried in a uniform drying atmosphere due to the
presence of the third solvent 620 on both sides of the blue ink
530, it can be formed into the blue light-emitting layer 531 having
a uniform thickness.
[0066] Referring to FIG. 9, after the third drying operation, all
solvents on the substrate 200, that is, the first solvent 600, the
second solvent 610, and the third solvent 620 may be removed as
they evaporate. All organic light-emitting ink 500, that is, the
red ink 510, the green ink 520, and the blue ink 530 may be dried
into the red light-emitting layer 511, the green light-emitting
layer 521, and the blue light-emitting layer 530, each having a
uniform thickness. In addition, the dummy patterns of the dummy
region 800 may remain in a final product or may be cut and
discarded.
[0067] FIGS. 10 and 11 are plan views illustrating methods of
manufacturing an organic luminescence display according to other
embodiments of the present invention. For simplicity, elements
which are the same as those of FIGS. 1 through 4 are indicated by
like reference numerals, and repeated description thereof will be
omitted.
[0068] Referring to FIG. 10, a dummy region 801 may be formed on a
substrate 200 in a non-display region adjacent to all edges of a
display region 700. That is, a plurality of dummy patterns shaped
like a plurality of pixels 710 may surround all of the pixels 710.
In addition, an inkjet printhead may selectively eject the organic
light-emitting ink 500 or the first solvent 600 onto the pixels 710
and the dummy patterns in a dot printing manner. In this case,
since the dummy patterns exist around all of the pixels 710, there
may be no need to eject the organic light-emitting ink 500 or the
first solvent 600 on a pixel defined layer 300.
[0069] Referring to FIG. 11, as in FIG. 10, a non-display region
802 may be formed on a substrate 200 in a non-display region
adjacent to all edges of the display region 700. However, one dummy
pattern may extend to surround all pixels 710. That is, the shape
of the dummy pattern may be different from that of the pixels 710.
In this case, since a single dummy pattern is formed, it may be
easy to eject a first solvent 600 onto the dummy pattern.
[0070] As described above, according to embodiments of the present
invention, ejected organic light-emitting ink is dried under a
uniform concentration of evaporating solvent molecules. Therefore,
an organic light-emitting layer having a uniform thickness can be
formed. In addition, since a solvent that is relatively less costly
than the organic light-emitting ink is used, material costs can be
saved.
[0071] While the present invention has been described in connection
with certain exemplary embodiments, it is to be understood that the
invention is not limited to the disclosed embodiments, but, on the
contrary, is intended to cover various modifications and equivalent
arrangements included within the spirit and scope of the appended
claims, and equivalents thereof.
* * * * *