U.S. patent application number 16/988954 was filed with the patent office on 2021-08-12 for mask assembly and method for manufacturing of the same.
The applicant listed for this patent is SAMSUNG DISPLAY CO., LTD.. Invention is credited to Dae Won BAEK, Eui Gyu KIM, Se Il KIM, Sang Min YI.
Application Number | 20210249603 16/988954 |
Document ID | / |
Family ID | 1000005049400 |
Filed Date | 2021-08-12 |
United States Patent
Application |
20210249603 |
Kind Code |
A1 |
KIM; Se Il ; et al. |
August 12, 2021 |
MASK ASSEMBLY AND METHOD FOR MANUFACTURING OF THE SAME
Abstract
A mask assembly and method for manufacturing of the same are
provided. A mask assembly includes: a mask frame including a first
mask opening and a second mask opening which are located side by
side in a first direction and defined by a support bar; a first
split mask overlapping the first mask opening; and a second split
mask overlapping the second mask opening, and the first split mask
and the second split mask are spaced apart from each other in a
region overlapping the support bar.
Inventors: |
KIM; Se Il; (Hwaseong-si,
KR) ; YI; Sang Min; (Suwon-si, KR) ; KIM; Eui
Gyu; (Suwon-si, KR) ; BAEK; Dae Won;
(Cheonan-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAMSUNG DISPLAY CO., LTD. |
Yongin-si |
|
KR |
|
|
Family ID: |
1000005049400 |
Appl. No.: |
16/988954 |
Filed: |
August 10, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C23C 14/24 20130101;
H01L 51/56 20130101; H01L 51/0011 20130101; C23C 14/042 20130101;
H01L 51/001 20130101 |
International
Class: |
H01L 51/00 20060101
H01L051/00; H01L 51/56 20060101 H01L051/56; C23C 14/04 20060101
C23C014/04; C23C 14/24 20060101 C23C014/24 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 7, 2020 |
KR |
10-2020-0014916 |
Claims
1. A mask assembly comprising: a mask frame comprising a first mask
opening and a second mask opening which are located side by side in
a first direction and defined by a support bar; a first split mask
overlapping the first mask opening; and a second split mask
overlapping the second mask opening, wherein the first split mask
and the second split mask are spaced apart from each other in a
region overlapping the support bar.
2. The mask assembly of claim 1, wherein the mask frame comprises:
a first side extending in a second direction intersecting the first
direction; and a second side in parallel with the first side and
spaced apart from the first side, wherein the support bar is
between the first side and the second side.
3. The mask assembly of claim 2, wherein a first end of the first
split mask overlaps the first side and a second end of the first
split mask overlaps the support bar, and wherein a first end of the
second split mask overlaps the support bar and a second end of the
second split mask overlaps the second side.
4. The mask assembly of claim 3, wherein the first split mask
comprises: first fixing portions overlapping the first side and the
support bar, respectively; first deposition pattern portions
between the first fixing portions and comprising a plurality of
first pattern openings; and first rib portions between the first
deposition pattern portions.
5. The mask assembly of claim 4, wherein the second split mask
comprises: second fixing portions overlapping the second side and
the support bar, respectively; second deposition pattern portions
between the second fixing portions and comprising a plurality of
second pattern openings; and second rib portions between the second
deposition pattern portions.
6. The mask assembly of claim 5, wherein the first fixing portion
overlapping the support bar and the second fixing portion
overlapping the support bar are adjacent to each other and spaced
apart from each other in a region overlapping the support bar.
7. The mask assembly of claim 5, wherein the first split mask
comprises a first welding portion on the first fixing portion
overlapping the first side, and a second welding portion on the
first fixing portion overlapping the support bar, and wherein the
second split mask comprises a third welding portion on the second
fixing portion overlapping the support bar, and a fourth welding
portion on the second fixing portion overlapping the second
side.
8. The mask assembly of claim 7, wherein the first split mask
further comprises a first half-etched portion at least at one of
the first and second ends of the first split mask, and the second
split mask further comprises a second half-etched portion at least
at one of the first and second ends of the second split mask.
9. The mask assembly of claim 8, wherein the first half-etched
portion of the first split mask overlaps the support bar and the
first fixing portion of the first split mask, and wherein the
second half-etched portion of the second split mask overlaps the
support bar and the second fixing portion of the second split
mask.
10. The mask assembly of claim 9, wherein the first half-etched
portion of the first split mask overlaps the second welding
portion, and the second half-etched portion of the second split
mask overlaps the third welding portion.
11. The mask assembly of claim 8, wherein the first half-etched
portion of the first split mask overlaps the first side and the
first fixing portion of the first split mask, and the second
half-etched portion of the second split mask overlaps the second
side and the second fixing portion of the second split mask.
12. The mask assembly of claim 11, wherein the first half-etched
portion of the first split mask overlaps the first welding portion,
and the second half-etched portion of the second split mask
overlaps the fourth welding portion.
13. The mask assembly of claim 8, wherein a thickness of the first
half-etched portion is 30% to 70% of a thickness of the first split
mask, and a thickness of the second half-etched portion is 30% to
70% of a thickness of the second split mask.
14. The mask assembly of claim 8, wherein the first half-etched
portion is continuous or spaced apart from a side of the first
split mask facing the second split mask, and the second half-etched
portion is continuous or spaced apart from a side of the second
split mask facing the first split mask.
15. The mask assembly of claim 7, wherein the first split mask
further comprises a first dummy pattern portion at least at one of
the first and second ends of the first split mask, and the second
split mask further comprises a second dummy pattern portion at
least at one of the first and second ends of the second split
mask.
16. The mask assembly of claim 15, wherein the first dummy pattern
portion of the first split mask is between the second welding
portion and the first fixing portion, and the second dummy pattern
portion of the second split mask is disposed between the third
welding portion and the second fixing portion.
17. The mask assembly of claim 16, wherein the first dummy pattern
portion of the first split mask does not overlap the second welding
portion of the first split mask and overlaps the support bar, and
the second dummy pattern portion of the second split mask does not
overlap the third welding portion of the second split mask and
overlaps the support bar.
18. The mask assembly of claim 15, wherein the first dummy pattern
portion of the first split mask is between the first welding
portion and the first fixing portion, and the second dummy pattern
portion of the second split mask is between the fourth welding
portion and the second fixing portion.
19. The mask assembly of claim 18, wherein the first dummy pattern
portion of the first split mask does not overlap the first welding
portion of the first split mask and overlaps the first side, and
the second dummy pattern portion of the second split mask does not
overlap the fourth welding portion of the second split mask and
overlaps the second side.
20. The mask assembly of claim 15, wherein the first dummy pattern
portion and the second dummy pattern portion comprise at least one
first dummy pattern portion and at least one second dummy pattern
portion, respectively.
21. A method of manufacturing a mask assembly, the method
comprising: preparing a mask frame comprising a first mask opening
and a second mask opening which are located side by side in a first
direction and defined by a support bar; aligning a split mask so as
to overlap the first mask opening and the second mask opening and
coupling the split mask to the mask frame; and cutting a region of
the split mask corresponding to the support bar to divide the split
mask into a first split mask and a second split mask.
22. The method of claim 21, wherein the mask frame comprises: a
first side extending in a second direction intersecting the first
direction; and a second side in parallel with the first side and
spaced apart from the first side, wherein the support bar is
between the first side and the second side.
23. The method of claim 22, wherein the coupling the split mask to
the mask frame comprises: performing first welding on a first end
of the split mask overlapping the first side; performing second
welding on a first region of the split mask overlapping the support
bar; performing third welding on a second region of the split mask
overlapping the support bar; and performing fourth welding on a
second end of the split mask overlapping the second side.
24. The method of claim 23, wherein the dividing the split mask
into the first split mask and the second split mask comprises:
cutting between a second welding portion formed by the second
welding and a third welding portion formed by the third welding in
the split mask.
25. A method of manufacturing a mask assembly, the method
comprising: preparing a mask frame comprising a first mask opening
and a second mask opening which are located side by side in a first
direction and defined by a support bar; aligning a first split mask
so as to overlap the first mask opening and the second mask opening
and coupling two regions of the first split mask adjacent to the
first mask opening to the mask frame; cutting a region of the first
split mask corresponding to the support bar; aligning a second
split mask so as to overlap the first split mask and the second
mask opening, and coupling two regions of the second split mask
adjacent to the second mask opening to the mask frame; and cutting
a region of the second split mask corresponding to the support
bar.
26. The method of claim 25, wherein the mask frame comprises: a
first side extending in a second direction intersecting the first
direction; and a second side in parallel with the first side and
spaced apart from the first side, wherein the support bar is
between the first side and the second side.
27. The method of claim 26, wherein the coupling the first split
mask to the mask frame comprises: performing first welding on an
end of the first split mask overlapping the first side; and
performing second welding on a region of the first split mask
overlapping the support bar.
28. The method of claim 27, wherein the cutting the first split
mask comprises cutting between the second mask opening and a second
welding portion of the first split mask formed by the second
welding.
29. The method of claim 28, wherein the coupling the second split
mask to the mask frame comprises: performing third welding on a
region of the second split mask overlapping the support bar; and
performing fourth welding on an end of the second split mask
overlapping the second side.
30. The method of claim 29, wherein the cutting the second split
mask comprises cutting between the first mask opening and a third
welding portion of the second split mask formed by the third
welding.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and the benefit of
Korean Patent Application No. 10-2020-0014916, filed on Feb. 7,
2020 in the Korean Intellectual Property Office, the entire
disclosure of which is incorporated herein by reference.
BACKGROUND
1. Field
[0002] Aspects of embodiments of the present disclosure relate to a
mask assembly and a method for manufacturing of the same.
2. Description of the Related Art
[0003] As a flat panel display, a liquid crystal display (LCD) and
an organic light emitting display (OLED) are widely used. The flat
panel display includes a metal layer having a specific pattern,
and, in the case of the organic light emitting display, an organic
light emitting layer having a specific pattern is formed for each
pixel. As a method of forming the metal layer and the organic light
emitting layer, a deposition method using a mask assembly may be
adopted.
[0004] The mask assembly includes a mask having an opening
corresponding to a pattern of a metal layer or an organic light
emitting layer, and a mask frame supporting the mask. In a split
mask method, the mask is divided into a plurality of split masks
having a stick, or bar, shape, and each split mask is fixed by
welding to the mask frame in a state in which it is tensioned in a
longitudinal direction thereof. The split mask method has an
advantage that products of high quality can be produced and used
and, also, the split mask is easy to repair.
[0005] Meanwhile, as a substrate for manufacturing an organic light
emitting display becomes larger, the size of the mask assembly also
increases. However, the size of the equipment for manufacturing the
mask assembly may have limitations of size.
SUMMARY
[0006] According to aspects of the present disclosure, a mask
assembly capable of use with a large-area substrate and preventing
or substantially preventing bending or deflection of a mask, and a
method of manufacturing the same, are provided.
[0007] However, aspects of the present disclosure are not
restricted to those set forth herein. The above and other aspects
of the present disclosure will become more apparent to one of
ordinary skill in the art to which the present disclosure pertains
by referencing the description of the present disclosure provided
below.
[0008] According to a mask assembly according to embodiments and a
method of manufacturing the same, it is possible to deposit a
deposition material on a large-area substrate by including a first
split mask and a second split mask. Further, it is possible to
prevent or substantially prevent deformation of the split mask due
to a volume difference for each region of the split mask by
including a half-etched portion. Further, it is possible to prevent
or substantially prevent bending of the split mask from extending
to a central portion thereof due to a volume difference for each
region of the split mask by including a dummy pattern portion.
[0009] However, aspects and effects of the present disclosure are
not limited to the aforementioned aspects and effects, and various
other aspects and effects are included in the present
specification.
[0010] According to one or more embodiments of the present
disclosure, a mask assembly includes: a mask frame including a
first mask opening and a second mask opening which are located side
by side in a first direction and defined by a support bar; a first
split mask overlapping the first mask opening; and a second split
mask overlapping the second mask opening, and the first split mask
and the second split mask are spaced apart from each other in a
region overlapping the support bar.
[0011] In an embodiment, the mask frame includes: a first side
extending in a second direction intersecting the first direction;
and a second side in parallel with the first side and spaced apart
from the first side, and the support bar is between the first side
and the second side.
[0012] In an embodiment, a first end of the first split mask
overlaps the first side and a second end of the first split mask
overlaps the support bar, and a first end of the second split mask
overlaps the support bar and a second end of the second split mask
overlaps the second side.
[0013] In an embodiment, the first split mask includes: first
fixing portions overlapping the first side and the support bar,
respectively; first deposition pattern portions between the first
fixing portions and including a plurality of first pattern
openings; and first rib portions between the first deposition
pattern portions.
[0014] In an embodiment, the second split mask includes: second
fixing portions overlapping the second side and the support bar,
respectively; second deposition pattern portions between the second
fixing portions and including a plurality of second pattern
openings; and second rib portions between the second deposition
pattern portions.
[0015] In an embodiment, the first fixing portion overlapping the
support bar and the second fixing portion overlapping the support
bar are adjacent to each other and spaced apart from each other in
a region overlapping the support bar.
[0016] In an embodiment, the first split mask includes a first
welding portion on the first fixing portion overlapping the first
side, and a second welding portion on the first fixing portion
overlapping the support bar, and the second split mask includes a
third welding portion on the second fixing portion overlapping the
support bar, and a fourth welding portion on the second fixing
portion overlapping the second side.
[0017] In an embodiment, the first split mask further comprises a
first half-etched portion at least at one of the first and second
ends of the first split mask, and the second split mask further
comprises a second half-etched portion at least at one of the first
and second ends of the second split mask.
[0018] In an embodiment, the first half-etched portion of the first
split mask overlaps the support bar and the first fixing portion of
the first split mask, and the second half-etched portion of the
second split mask overlaps the support bar and the second fixing
portion of the second split mask.
[0019] In an embodiment, the first half-etched portion of the first
split mask overlaps the second welding portion, and the second
half-etched portion of the second split mask overlaps the third
welding portion.
[0020] In an embodiment, the first half-etched portion of the first
split mask overlaps the first side and the first fixing portion of
the first split mask, and the second half-etched portion of the
second split mask overlaps the second side and the second fixing
portion of the second split mask.
[0021] In an embodiment, the first half-etched portion of the first
split mask overlaps the first welding portion, and the second
half-etched portion of the second split mask overlaps the fourth
welding portion.
[0022] In an embodiment, a thickness of the first half-etched
portion is 30% to 70% of a thickness of the first split mask, and a
thickness of the second half-etched portion is 30% to 70% of a
thickness of the second split mask.
[0023] In an embodiment, the first half-etched portion is
continuous or spaced apart from a side of the first split mask
facing the second split mask, and the second half-etched portion is
continuous or spaced apart from a side of the second split mask
facing the first split mask.
[0024] In an embodiment, the first split mask further comprises a
first dummy pattern portion at least at one of the first and second
ends of the first split mask, and the second split mask further
comprises a second dummy pattern portion at least at one of the
first and second ends of the second split mask.
[0025] In an embodiment, the first dummy pattern portion of the
first split mask is between the second welding portion and the
first fixing portion, and the second dummy pattern portion of the
second split mask is between the third welding portion and the
second fixing portion.
[0026] In an embodiment, the first dummy pattern portion of the
first split mask does not overlap the second welding portion of the
first split mask and overlaps the support bar, and the second dummy
pattern portion of the second split mask does not overlap the third
welding portion of the second split mask and overlaps the support
bar.
[0027] In an embodiment, the first dummy pattern portion of the
first split mask is between the first welding portion and the first
fixing portion, and the second dummy pattern portion of the second
split mask is between the fourth welding portion and the second
fixing portion.
[0028] In an embodiment, the first dummy pattern portion of the
first split mask does not overlap the first welding portion of the
first split mask and overlaps the first side, and the second dummy
pattern portion of the second split mask does not overlap the
fourth welding portion of the second split mask and overlaps the
second side.
[0029] In an embodiment, the first dummy pattern portion and the
second dummy pattern portion include at least one first dummy
pattern portion and at least one second dummy pattern portion,
respectively.
[0030] According to one or more embodiments of the present
disclosure, a method of manufacturing a mask assembly includes:
preparing a mask frame including a first mask opening and a second
mask opening which are located side by side in a first direction
and defined by a support bar; aligning a split mask so as to
overlap the first mask opening and the second mask opening and
coupling the split mask to the mask frame; and cutting a region of
the split mask corresponding to the support bar to divide the split
mask into a first split mask and a second split mask.
[0031] In an embodiment, the mask frame includes: a first side
extending in a second direction intersecting the first direction;
and a second side in parallel with the first side and spaced apart
from the first side, and the support bar is between the first side
and the second side.
[0032] In an embodiment, the coupling the split mask to the mask
frame comprises: performing first welding on a first end of the
split mask overlapping the first side; performing second welding on
a first region of the split mask overlapping the support bar;
performing third welding on a second region of the split mask
overlapping the support bar; and performing fourth welding on a
second end of the split mask overlapping the second side.
[0033] In an embodiment, the dividing the split mask into the first
split mask and the second split mask comprises cutting between a
second welding portion formed by the second welding and a third
welding portion formed by the third welding in the split mask.
[0034] According to one or more embodiments of the present
disclosure, a method of manufacturing a mask assembly includes:
preparing a mask frame including a first mask opening and a second
mask opening which are located side by side in a first direction
and defined by a support bar; aligning a first split mask so as to
overlap the first mask opening and the second mask opening and
coupling two regions of the first split mask adjacent to the first
mask opening to the mask frame; cutting a region of the first split
mask corresponding to the support bar; aligning a second split mask
so as to overlap the first split mask and the second mask opening
and coupling two regions of the second split mask adjacent to the
second mask opening to the mask frame; and cutting a region of the
second split mask corresponding to the support bar.
[0035] In an embodiment, the mask frame includes a first side
extending in a second direction intersecting the first direction;
and a second side in parallel with the first side and spaced apart
from the first side, and the support bar is between the first side
and the second side.
[0036] In an embodiment, the coupling the first split mask to the
mask frame comprises: performing first welding on an end of the
first split mask overlapping the first side; and performing second
welding on a region of the first split mask overlapping the support
bar.
[0037] In an embodiment, the cutting the first split mask comprises
cutting between the second mask opening and a second welding
portion of the first split mask formed by the second welding.
[0038] In an embodiment, the coupling the second split mask to the
mask frame comprises: performing third welding on a region of the
second split mask overlapping the support bar; and performing
fourth welding on an end of the second split mask overlapping the
second side.
[0039] In an embodiment, the cutting the second split mask
comprises cutting between the first mask opening and a third
welding portion of the second split mask formed by the third
welding.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] The above and other aspects and features of the present
disclosure will become more apparent by describing in further
detail some example embodiments thereof with reference to the
attached drawings, in which:
[0041] FIG. 1 is a perspective view of a mask assembly according to
an embodiment of the present disclosure;
[0042] FIG. 2 is a perspective view of a split mask of FIG. 1;
[0043] FIG. 3 is a perspective view schematically showing a mask
assembly according to an embodiment;
[0044] FIG. 4 is a plan view schematically illustrating a split
mask according to an embodiment;
[0045] FIG. 5 is a plan view schematically illustrating a mask
assembly according to an embodiment;
[0046] FIG. 6 is a cross-sectional view schematically showing a
structure taken along the line I-I' of FIG. 5;
[0047] FIGS. 7 to 9 are views illustrating steps of a method of
manufacturing a mask assembly according to an embodiment;
[0048] FIGS. 10 to 12 are views illustrating steps of a method of
manufacturing a mask assembly according to another embodiment;
[0049] FIG. 13 is a plan view schematically showing a mask assembly
according to another embodiment;
[0050] FIG. 14 is a cross-sectional view schematically showing a
structure taken along the line II-II' of FIG. 13;
[0051] FIG. 15 is a cross-sectional view schematically showing a
structure according to another embodiment, taken along the line
II-II' of FIG. 13;
[0052] FIG. 16 is a cross-sectional view schematically showing a
structure according to another embodiment, taken along the line
II-II' of FIG. 13;
[0053] FIG. 17 is a cross-sectional view schematically showing a
structure taken along the line III-III' of FIG. 13;
[0054] FIG. 18 is a plan view schematically showing a mask assembly
according to another embodiment;
[0055] FIG. 19 is a cross-sectional view schematically showing a
structure taken along the line IV-IV' of FIG. 18;
[0056] FIG. 20 is a cross-sectional view schematically showing a
structure according to another embodiment, taken along the line
IV-IV' of FIG. 18;
[0057] FIG. 21 is a cross-sectional view schematically showing a
structure taken along the line V-V' of FIG. 18;
[0058] FIG. 22 is a view schematically illustrating a deposition
process using a mask assembly according to an embodiment; and
[0059] FIG. 23 is a cross-sectional view schematically showing an
organic light emitting display device according to an
embodiment.
DETAILED DESCRIPTION
[0060] The present invention will now be described more fully
herein with reference to the accompanying drawings, in which some
example embodiments of the invention are shown. This invention may,
however, be embodied in different forms and should not be construed
as limited to the embodiments set forth herein. Rather, these
embodiments are provided so that this disclosure will be thorough
and complete, and will fully convey the scope of the invention to
those skilled in the art.
[0061] It is also to be understood that when a layer is referred to
as being "on" another layer or substrate, it may be directly on the
other layer or substrate, or one or more intervening layers may
also be present. The same reference numbers indicate the same or
like components throughout the specification. The shapes, sizes,
ratios, angles, numbers, etc. disclosed in the drawings for
describing the embodiments may be examples, and the present
invention is not limited to those illustrated. As used herein, the
term "and/or" includes any and all combinations of one or more of
the associated listed items.
[0062] Spatially relative terms, such as "beneath," "below,"
"lower," "above," "upper," and the like, may be used herein for
ease of description to describe one element or feature's
relationship to another element(s) or feature(s) as illustrated in
the figures. It is to be understood that the spatially relative
terms are intended to encompass different orientations of the
device in use or operation in addition to the orientation depicted
in the figures. For example, if the device in the figures is turned
over, elements described as "below" or "beneath" other elements or
features would then be oriented "above" the other elements or
features. Thus, the example term "below" can encompass both an
orientation of above and below. For example, the device may be
otherwise oriented (e.g., rotated 90 degrees or at other
orientations) and the spatially relative descriptors used herein
interpreted accordingly.
[0063] It is to be understood that, although the terms "first,"
"second," etc. may be used herein to describe various elements,
components, regions, layers, and/or sections, these elements,
components, regions, layers, and/or sections should not be limited
by these terms. These terms are used to distinguish one element,
component, region, layer, or section from another element,
component, region, layer, or section. Thus, a "first" element,
component, region, layer, or section discussed below could be
termed a "second" element, component, region, layer, or section
without departing from the teachings of the inventive concept.
[0064] The meaning of "include" or "comprise" may specify a
property, a fixed number, a step, an operation, an element, a
component, or a combination thereof, but does not exclude other
properties, fixed numbers, steps, operations, elements, components,
or combinations thereof.
[0065] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which example
embodiments of the inventive concepts belong. It is to be further
understood that terms, such as those defined in commonly-used
dictionaries, should be interpreted as having a meaning that is
consistent with their meaning in the context of the relevant art
and are not to be interpreted in an idealized or overly formal
sense unless expressly so defined herein.
[0066] Herein, some example embodiments of the present disclosure
will be described in further detail with reference to the
accompanying drawings.
[0067] FIG. 1 is a perspective view of a mask assembly according to
an embodiment of the present disclosure; and FIG. 2 is a
perspective view of a split mask of FIG. 1.
[0068] Referring to FIGS. 1 and 2, a mask assembly 100 according to
an embodiment may include a mask frame 130 and a plurality of split
masks 140 disposed on the mask frame 130.
[0069] The mask frame 130 forms an outer frame of the mask assembly
100 and may have a rectangular band shape in which a frame opening
132 is formed at a central portion thereof. The mask frame 130 may
have a thickness (e.g., a predetermined thickness) in a third
direction D3 to stably support the split masks 140 or the like. The
mask frame 130 may include a pair of long sides and a pair of short
sides, and the frame opening 132 may be disposed at the center
thereof. For example, the pair of long sides may extend in a first
direction D1 and be disposed parallel to each other in a second
direction D2, and the pair of short sides may extend in the second
direction D2 and be disposed parallel to each other in the first
direction D1.
[0070] In an embodiment, the planar shape of the mask opening 132
may be approximately rectangular. The mask opening 132 may provide
a path through which a deposition material passes. In another
embodiment, the mask frame 130 may have a rectangular band shape in
which both pairs of sides have the same length, and the planar
shape of the mask opening 132 may be square. The mask frame 130 may
include a material having high rigidity, for example, a metal, such
as stainless steel.
[0071] The split mask 140 may be disposed on the mask frame 130.
The split mask 140 may have a first surface (upper surface in the
drawing) and a second surface (lower surface in the drawing). The
first surface may be a surface in contact with a substrate (not
shown) during a deposition process, and the second surface may be a
surface opposite to the first surface and a surface toward which a
deposition material is provided. The second surface of the split
mask 140 may be in contact with the mask frame 130.
[0072] The split mask 140 may have a shape in which its length
(e.g., length in the second direction D2) is greater than its width
(e.g., width in the first direction D1). In an embodiment, the
split mask 140 may be divided into a plurality of parts extending
in the first direction D1 and adjacent in the second direction D2.
In another embodiment, the split mask 140 may be a mother mask
integrally formed with a planar area covering the frame opening
132. In an embodiment, the split mask 140 may be a fine metal mask
made of a metal material. The split mask 140 may be made of metal,
such as stainless steel, nickel, cobalt, or an alloy thereof. In
some embodiments, the split mask 140 may have magnetic
properties.
[0073] The split mask 140 may include fixing portions 142 located
at both ends in its length direction (i.e., the second direction
D2), a plurality of deposition pattern portions 144 located closer
to a center portion than the fixing portions 142, and rib portions
146 located between the deposition pattern portions 144.
[0074] The fixing portion 142 is a portion which is in contact with
and coupled to the mask frame 130. For example, the fixing portion
142 may be welded and coupled to the mask frame 130. The method of
welding is not particularly limited, and may include, for example,
laser welding, resistance heating welding, and the like. The fixing
portion 142 may include a welding portion WE formed by being welded
to the mask frame 130. The welding portion WE may be formed as a
plurality of spots in a region corresponding to the fixing portion
142. In FIG. 1, the welding portion WE is illustrated as being
arranged in one row, but the present disclosure is not limited
thereto. The welding portion WE may be arranged in a plurality of
rows, such as two or more rows.
[0075] The deposition pattern portion 144 is a portion in which a
plurality of pattern openings 145 are formed to provide a path
through which the deposition material passes. The plurality of
deposition pattern portions 144 may be disposed in the length
direction (i.e., the second direction D2) of the split mask 140.
FIG. 1 illustrates a case in which three deposition pattern
portions 144 are spaced apart in the second direction D2, but the
present disclosure is not limited thereto. Further, the rib portion
146 may be disposed between the deposition pattern portions 144
adjacent to each other in the second direction D2. The rib portion
146 may be a reference for distinguishing the deposition pattern
portions 144 adjacent to each other in the second direction D2. The
rib portion 146 may block the deposition material from passing
therethrough because no pattern opening is formed.
[0076] The deposition pattern portion 144 may correspond to one
display device (for example, an organic light emitting display
device). In this case, patterns corresponding to a plurality of
display devices may be concurrently (e.g., simultaneously)
deposited in a single process using one mask assembly 100. That is,
the mask assembly 100 may correspond to one mother substrate and
concurrently (e.g., simultaneously) form patterns corresponding to
a plurality of display devices on the mother substrate.
[0077] The pattern opening 145 is an opening passing through the
first surface and the second surface of the split mask 140. The
pattern openings 145 of the split masks 140 arranged on the
substrate may expose a deposition target region of the substrate.
That is, the pattern opening 145 may have substantially the same
planar shape as a deposition pattern to be formed. FIGS. 1 and 2
illustrate that the pattern openings 145 are spaced apart in the
first direction D1 and the second direction D2 and arranged in a
substantially matrix shape with a dot shape in a plan view, but the
present disclosure is not limited thereto. For example, the pattern
opening 145 may have a slit shape extending in the first direction
D1 or the second direction D2 in a plan view.
[0078] The split mask 140 may be fixed to the mask frame 130 by
welding in a state in which a tensile force is applied to both ends
of the split mask 140 along the first direction D1 or the second
direction D2. In another embodiment, the split mask 140 may be
stretched in both the first direction D1 and the second direction
D2.
[0079] In an embodiment, gap masks 150 may be disposed between the
plurality of split masks 140. The gap masks 150 may be disposed at
intervals between the split masks 140 to block the deposition
material from passing between the split masks 140. The gap mask 150
may have a same length (length in the second direction D2) as the
split mask 140. The gap mask 150 may not be provided with an
opening to block the passage of the deposition material. In FIG. 1,
a case in which the gap masks 150 are provided has been
illustrated, but the present disclosure is not limited thereto,
and, in an embodiment, the gap masks 150 may be omitted.
[0080] Meanwhile, as the substrate becomes larger, the size of the
mask assembly is increased. However, since there is a limit in the
size of the equipment for manufacturing the split masks to be
coupled to the mask assembly, such as exposure equipment and photo
masks, it is difficult to cope with the large-area substrate.
[0081] Herein, a mask assembly capable of use with a large-area
substrate and a manufacturing method thereof will be described.
[0082] FIG. 3 is a perspective view schematically showing a mask
assembly according to an embodiment; FIG. 4 is a plan view
schematically illustrating a split mask according to an embodiment;
FIG. 5 is a plan view schematically illustrating a mask assembly
according to an embodiment; and FIG. 6 is a cross-sectional view
schematically showing a structure taken along the line I-I' of FIG.
5.
[0083] Referring to FIGS. 3 to 6, a mask assembly 100 according to
an embodiment may include a mask frame 130 and a plurality of split
masks 140 disposed on the mask frame 130.
[0084] The mask frame 130 may include a pair of long sides and a
pair of short sides and include a plurality of frame openings 132
at a central portion thereof. The pair of long sides may include a
first side 133a extending in the first direction D1, and a second
side 133b spaced apart from and parallel to the first side 133a.
The pair of short sides may include a third side 133c connecting
the first side 133a to the second side 133b in the second direction
D2, and a fourth side 133d disposed to be parallel to the third
side 133c and spaced apart from the third side 133c. In the present
embodiment, the long sides and the short sides have been described,
but the present disclosure is not limited thereto. That is, the
sides may have the same length or the positions of the long side
and the short side may be changed.
[0085] The mask frame 130 may include a first support part 135a and
a second support part 135b passing through the central portion
thereof. The first support part 135a may be disposed in parallel
with the first side 133a and the second side 133b, and may connect
the third side 133c to the fourth side 133d. The first support part
135a may extend in the first direction D1 perpendicular to the
third side 133c and the fourth side 133d. The second support part
135b may perpendicularly intersect the first support part 135a. The
second support part 135b may be disposed in parallel with the third
side 133c and the fourth side 133d and may extend in the second
direction D2 perpendicularly intersecting the first side 133a and
the second side 133b.
[0086] The mask frame 130 may include therein first to fourth mask
openings 132a, 132b, 132c, and 132d through which the deposition
material passes. The first mask opening 132a may be an opening
defined by the first side 133a, the third side 133c, the first
support part 135a, and the second support part 135b. The second
mask opening 132b may be an opening defined by the second side
133b, the third side 133c, the first support part 135a, and the
second support part 135b. The third mask opening 132c may be an
opening defined by the first side 133a, the fourth side 133d, the
first support part 135a, and the second support part 135b. The
fourth mask opening 132d may be an opening defined by the second
side 133b, the fourth side 133d, the first support part 135a, and
the second support part 135b. In the present embodiment, a case in
which four openings are formed in the mask frame 130 through two
support parts has been illustrated, but the present disclosure is
not limited thereto, and six or more openings may be formed through
three or more support parts.
[0087] The planar shape of the first mask opening 132a, the second
mask opening 132b, the third mask opening 132c and the fourth mask
opening 132d may be substantially rectangular. Each of the first
mask opening 132a, the second mask opening 132b, the third mask
opening 132c and the fourth mask opening 132d may correspond to the
size of one mother substrate described with reference to FIG. 1.
For example, the size of one mask assembly described with reference
to FIG. 1 may correspond to the size of each of the first mask
opening 132a, the second mask opening 132b, the third mask opening
132c, and the fourth mask opening 132d.
[0088] First split masks 140 and second split masks 160 may be
disposed on the mask frame 130, respectively. The first split mask
140 may include first fixing portions 142 located at both ends in
its length direction (i.e., the second direction D2), a plurality
of first deposition pattern portions 144 located closer to the
center of the first split mask 140 than the first fixing portions
142, and first rib portions 146 located between the first
deposition pattern portions 144. The second split mask 160 may
include second fixing portions 162 located at both ends in its
length direction (i.e., the second direction D2), a plurality of
second deposition pattern portions 164 located closer to the center
of the second split mask 160 than the second fixing portions 162,
and second rib portions 166 located between the second deposition
pattern portions 164.
[0089] The first deposition pattern portion 144 of the first split
mask 140 may include a plurality of first pattern openings 145, and
the second deposition pattern portion 164 of the second split mask
160 may include a plurality of second pattern openings 165. In an
embodiment, the first pattern openings 145 and the second pattern
openings 165 have the same pattern shape, and a resultant product
of the same deposition material may be deposited. In another
embodiment, the first pattern openings 145 and the second pattern
openings 165 have different pattern shapes, and different resultant
products of deposition materials may be deposited. Accordingly,
when the same deposition material is deposited concurrently (e.g.,
simultaneously) using one mask assembly 100, deposition materials
having different shapes may be deposited on the substrate.
[0090] As shown in FIG. 5, the first split mask 140 may be disposed
to overlap the first mask opening 132a. A first end of the first
split mask 140 may overlap the first side 133a of the mask frame
130, and a second end of the first split mask 140 may overlap the
first support part 135a of the mask frame 130. A first fixing
portion 142 may be disposed at the first end of the first split
mask 140, and the first fixing portion 142 and the first side 133a
of the mask frame 130 may overlap each other. A first welding
portion WE1 may be disposed on the first fixing portion 142
overlapping the first side 133a of the mask frame 130 to be coupled
to the first side 133a of the mask frame 130. A first fixing
portion 142 may be disposed at the second end of the first split
mask 140, and the first fixing portion 142 and the first support
part 135a may overlap each other. A second welding portion WE2 may
be disposed on the first fixing portion 142 overlapping the first
support part 135a to be coupled to the first support part 135a.
[0091] The second split mask 160 may be disposed to overlap the
second mask opening 132b. A first end of the second split mask 160
may overlap the first support part 135a of the mask frame 130, and
a second end of the second split mask 160 may overlap the second
side 133b of the mask frame 130. A second fixing portion 162 may be
disposed at the first end of the second split mask 160, and the
second fixing portion 162 and the first support part 135a of the
mask frame 130 may overlap each other. A third welding portion WE3
may be disposed on the second fixing portion 162 overlapping the
first support part 135a of the mask frame 130 to be coupled to the
first support part 135a of the mask frame 130. A second fixing
portion 162 may be disposed at the second end of the second split
mask 160, and the second fixing portion 162 and the second side
133b of the mask frame 130 may overlap each other. A fourth welding
portion WE4 may be disposed on the second fixing portion 162
overlapping the second side 133b to be coupled to the second side
133b of the mask frame 130.
[0092] As shown in FIGS. 5 and 6, the first split mask 140 and the
second split mask 160 may be spaced apart from each other. That is,
the first split mask 140 and the second split mask 160 may be
spaced apart from each other in a region overlapping the first
support part 135a of the mask frame 130. A side of the first split
mask 140 and a side of the second split mask 160 adjacent to the
side of the first split mask 140 may be spaced apart from each
other by a gap (e.g., a predetermined gap) G1. In an embodiment,
the gap G1 between the first split mask 140 and the second split
mask 160 may be 0.1 mm or more, and the first split mask 140 and
the second split mask 160 may be sufficiently spaced apart from
each other such as not to interfere with each other. The gap G1
between the first split mask 140 and the second split mask 160
separated from each other may be smaller than a width of the first
support part 135a of the mask frame 130.
[0093] In an embodiment, since the first split mask 140 and the
second split mask 160 are spaced apart from each other, even if
deformation occurs in one split mask, the deformation can be
prevented or substantially prevented from being transferred to
another adjacent split mask. Thus, the pattern accuracy of the
deposition material deposited on the substrate through the mask
frame 130 can be prevented or substantially prevented from being
lowered.
[0094] As illustrated in FIG. 3, a first gap mask 150 may be
disposed between the first split masks 140, and a second gap mask
170 may be disposed between the second split masks 160. In the
first gap mask 150, a third fixing portion 152 overlapping the
first side 133a of the mask frame 130 may be disposed at a first
end of the first gap mask 150, a third fixing portion 152
overlapping the first support part 135a of the mask frame 130 may
be disposed at a second end of the first gap mask 150, and a first
blocking portion 154 may be disposed between the third fixing
portions 152. A fifth welding portion WE5 may be disposed at the
third fixing portion 152 at the first end of the first gap mask 150
to be coupled to the first side 133a of the mask frame 130, and a
sixth welding portion WE6 may be disposed at the third fixing
portion 152 at the second end of the first gap mask 150 to be
coupled to the first support part 135a of the mask frame 130.
[0095] In the second gap mask 170, similarly, a fourth fixing
portion 172 overlapping the first support part 135a of the mask
frame 130 may be disposed at a first end of the second gap mask
170, a fourth fixing portion 172 overlapping the second side 133b
of the mask frame 130 may be disposed at a second end of the second
gap mask 170, and a second blocking portion 174 may be disposed
between the fourth fixing portions 172. A seventh welding portion
WE7 may be disposed at the fourth fixing portion 172 at the first
end of the second gap mask 170 to be coupled to the first support
part 135a of the mask frame 130, and an eighth welding portion WE8
may be disposed at the fourth fixing portion 172 at the second end
of the second gap mask 170 to be coupled to the second side 133b of
the mask frame 130.
[0096] The first gap mask 150 and the second gap mask 170 may be
spaced apart from each other. That is, the first gap mask 150 and
the second gap mask 170 may be spaced apart from each other in a
region overlapping the first support part 135a of the mask frame
130. A side of the first gap mask 150 and a side of the second gap
mask 170 adjacent to the side of the first gap mask 150 may be
spaced apart from each other by the gap G1. In an embodiment, the
gap G1 between the first gap mask 150 and the second gap mask 170
may be 0.1 mm or more, and the first gap mask 150 and the second
gap mask 170 may be sufficiently spaced apart from each other such
as not to interfere with each other. The gap G1 between the first
gap mask 150 and the second gap mask 170 separated from each other
may be smaller than the width of the first support part 135a of the
mask frame 130.
[0097] Herein, a method of manufacturing the mask assembly of FIG.
3 described above will be described.
[0098] FIGS. 7 to 9 are views illustrating steps of a method of
manufacturing a mask assembly according to an embodiment. FIGS. 10
to 12 are views illustrating steps of a method of manufacturing a
mask assembly according to another embodiment.
[0099] Referring to FIGS. 7 and 8, a method of manufacturing a mask
assembly 100 according to an embodiment may include a step of
preparing a plurality of split masks, gap masks, and a mask frame,
a step of aligning and coupling the split masks and the gap masks,
and a step of cutting the split masks and the gap masks.
[0100] The step of preparing a plurality of split masks, gap masks,
and a mask frame is a step of manufacturing and preparing split
masks 120, gap masks 180, and a mask frame 130. In an embodiment,
the mask frame 130 is prepared, which includes a first mask opening
132a, a second mask opening 132b, a third mask opening 132c, and a
fourth opening mask 132d defined by a first support part 135a
extending in the first direction D1 and a second support part 135b
extending in the second direction D2.
[0101] Further, the split mask 120 is prepared, which includes
first fixing portions 142 disposed at a first side thereof, first
deposition pattern portions 144 having a plurality of first pattern
openings 145 adjacent to the first fixing portions 142, a first rib
portion 146 disposed between the first deposition pattern portions
144, second fixing portions 162 disposed at a second side thereof,
second deposition pattern portions 164 having a plurality of second
pattern openings 165 adjacent to the second fixing portions 162,
and a second rib portion 166 disposed between the second deposition
pattern portions 164.
[0102] A process for forming a deposition pattern portion is
performed on each of the first deposition pattern portion 144 and
the second deposition pattern portion 164 of the split mask 120.
For example, the plurality of first pattern openings 145 of the
first deposition pattern portion 144 may be formed by applying a
photoresist to the first deposition pattern portion 144 and
performing exposure, development, and etching processes. Further,
the plurality of second pattern openings 165 of the second
deposition pattern portion 164 may be formed by applying a
photoresist to the second deposition pattern portion 164 and
performing exposure, development, and etching processes. In an
embodiment, the first pattern openings 145 of the deposition
pattern portion 144 and the second pattern openings 165 of the
second deposition pattern portion 164 may be formed, respectively,
by separate processes.
[0103] Further, the gap mask 180 is prepared, which includes third
fixing portions 152 disposed at a first side thereof, fourth fixing
portions 172 disposed at a second side thereof, and a first
blocking portion 154 and a second blocking portion 174 disposed
between the third fixing portions 152 and the fourth fixing
portions 172, respectively.
[0104] The step of aligning and coupling the split masks and the
gap masks is a step of aligning the split masks 120 and the gap
masks 180 on the mask frame 130 and then coupling them.
[0105] As shown in FIG. 8, the split masks 120 and the gap masks
180 are aligned on the mask frame 130. The split masks 120 and the
gap masks 180 are disposed to overlap the first mask opening 132a
and the second mask opening 132b of the mask frame 130. Although
not illustrated, the split masks 120 and the gap masks 180 may also
be disposed to overlap the third mask opening 132c and the fourth
mask opening 132d of the mask frame 130.
[0106] In this case, each of the split mask 120 and the gap mask
180 may be tensioned by fixing both ends thereof by clamping. For
example, a tensile force may be applied to the split mask 120 and
the gap mask 180 in the second direction D2 by clamping.
[0107] Then, referring to FIG. 9, the split masks 120 and the gap
masks 180 aligned on the mask frame 130 are welded and coupled to
the mask frame 130.
[0108] In an embodiment, a first welding portion WE1 is formed by
performing welding on the first fixing portion 142 of the split
mask 120 overlapping the first side 133a of the mask frame 130,
thereby coupling the first side of the split mask 120 with the mask
frame 130. At the same time, for example, a fifth welding portion
WE5 is formed by performing welding on the third fixing portion 152
of the gap mask 180 overlapping the first side 133a of the mask
frame 130, thereby coupling the first side of the gap mask 180 with
the mask frame 130.
[0109] Then, a second welding portion WE2 is formed by performing
welding on the first fixing portion 142 of the split mask 120
overlapping the first support part 135a of the mask frame 130,
thereby coupling a portion of the split mask 120 with the mask
frame 130. At the same time, for example, a sixth welding portion
WE6 is formed by performing welding on the third fixing portion 152
of the gap mask 180 overlapping the first support part 135a of the
mask frame 130, thereby coupling a portion of the gap mask 180 with
the mask frame 130.
[0110] Subsequently, a third welding portion WE3 is formed by
performing welding on a second fixing portion 162 of the split mask
120 overlapping the first support part 135a of the mask frame 130,
thereby coupling a portion of the split mask 120 with the mask
frame 130. At the same time, for example, a seventh welding portion
WE7 is formed by performing welding on the fourth fixing portion
172 of the gap mask 180 overlapping the first support part 135a of
the mask frame 130, thereby coupling a portion of the gap mask 180
with the mask frame 130.
[0111] Then, a fourth welding portion WE4 is formed by performing
welding on the second fixing portion 162 of the split mask 120
overlapping the second side 133b of the mask frame 130, thereby
coupling a portion of the split mask 120 with the mask frame 130.
At the same time, for example, an eighth welding portion WE8 is
formed by performing welding on the fourth fixing portion 172 of
the gap mask 180 overlapping the second side 133b of the mask frame
130, thereby coupling a portion of the gap mask 180 with the mask
frame 130.
[0112] The step of cutting the split masks and the gap masks is a
step of cutting the split mask 120 and the gap mask 180.
[0113] As shown in FIG. 9, first cutting TR1 is performed on one
side of the split mask 120 overlapping the first side 133a of the
mask frame 130, for example, between the first welding portion WE1
of the split mask 120 and one side of the split mask 120. At the
same time, for example, first cutting TR1 is performed on one side
of the gap mask 180 overlapping the first side 133a of the mask
frame 130, for example, between the fifth welding portion WE5 of
the gap mask 180 and one side of the gap mask 180.
[0114] In an embodiment, cutting may be performed using a knife or
a laser.
[0115] Subsequently, second cutting TR2 is performed on a portion
of the split mask 120 overlapping the first support part 135a of
the mask frame 130, for example, between the second welding portion
WE2 and the third welding portion WE3 of the split mask 120. At the
same time, for example, second cutting TR2 is performed on a
portion of the gap mask 180 overlapping the first support part 135a
of the mask frame 130, for example, between the sixth welding
portion WE6 and the seventh welding portion WE7 of the gap mask
180.
[0116] Then, third cutting TR3 is performed on the other side of
the split mask 120 overlapping the second side 133b of the mask
frame 130, for example, between the fourth welding portion WE4 of
the split mask 120 and the other side of the split mask 120. At the
same time, for example, third cutting TR3 is performed on the other
side of the gap mask 180 overlapping the second side 133b of the
mask frame 130, for example, between the eighth welding portion WE8
of the gap mask 180 and the other side of the gap mask 180.
[0117] As a result, as shown in FIG. 3, the first split mask 140
and the first gap mask 150 overlapping the first mask opening 132a
of the mask frame 130 may be formed, and the second split mask 160
and the second gap mask 170 overlapping the second mask opening
132b of the mask frame 130 may be formed, thereby manufacturing the
mask assembly 100.
[0118] In the above-described embodiment, through three cutting
processes, the split mask 120 may be divided into the first split
mask 140 and the second split mask 160 to be separated from each
other, and the gap mask 180 may be divided into the first gap mask
150 and the second gap mask 170 to be separated from each
other.
[0119] Herein, a method of manufacturing the mask assembly 100
according to another embodiment will be described. In the following
embodiment, a repeated description of the same processes as in
FIGS. 7 to 9 may be omitted.
[0120] As described above with reference to FIGS. 7 to 8, the split
mask 120 and the gap mask 180 are aligned and disposed on the mask
frame 130.
[0121] Then, referring to FIG. 10, a first welding portion WE1 is
formed by performing welding on the first fixing portion 142 of the
split mask 120 overlapping the first side 133a of the mask frame
130, thereby coupling a first side of the split mask 120 with the
mask frame 130. At the same time, for example, a fifth welding
portion WE5 is formed by performing welding on the third fixing
portion 152 of the gap mask 180 overlapping the first side 133a of
the mask frame 130, thereby coupling a first side of the gap mask
180 with the mask frame 130.
[0122] Then, a second welding portion WE2 is formed by performing
welding on the first fixing portion 142 of the split mask 120
overlapping the first support part 135a of the mask frame 130,
thereby coupling a portion of the split mask 120 with the mask
frame 130. At the same time, for example, a sixth welding portion
WE6 is formed by performing welding on the third fixing portion 152
of the gap mask 180 overlapping the first support part 135a of the
mask frame 130, thereby coupling a portion of the gap mask 180 with
the mask frame 130.
[0123] Then, first cutting TR1 is performed on one side of the
split mask 120 overlapping the first side 133a of the mask frame
130, for example, between the first welding portion WE1 of the
split mask 120 and the first side of the split mask 120. At the
same time, for example, first cutting TR1 is performed on one side
of the gap mask 180 overlapping the first side 133a of the mask
frame 130, for example, between the fifth welding portion WE5 of
the gap mask 180 and the first side of the gap mask 180. In an
embodiment, cutting may be performed using a knife or a laser.
[0124] Subsequently, second cutting TR2 is performed on a portion
of the split mask 120 overlapping the first support part 135a of
the mask frame 130, for example, between the second welding portion
WE2 and the third welding portion WE3 of the split mask 120. At the
same time, for example, second cutting TR2 is performed a portion
of the gap mask 180 overlapping the first support part 135a of the
mask frame 130, for example, between the sixth welding portion WE6
and the seventh welding portion WE7 of the gap mask 180.
[0125] Then, referring to FIG. 11, the remaining portion of the
split mask not coupled with the mask frame 130 is removed by the
second cutting TR2. Accordingly, the first split mask 140 and the
first gap mask 180 may be coupled on the mask frame 130. In the
present embodiment, the portion of the split mask overlapping the
second mask opening 132b is removed since the alignment of the
deposition pattern portion overlapping the first mask opening 132a
and the alignment of the deposition pattern portion overlapping the
second mask opening 132b may be different from each other since the
pattern openings of the deposition pattern portion of the split
mask may be formed by two separate processes.
[0126] Then, referring to FIG. 12, a prepared third split mask 190
may be superimposed and aligned on the mask frame 130 to which the
first split mask 140 is coupled and a third gap mask 200 is
superimposed and aligned on the mask frame 130 to which the first
gap mask 150 is coupled. That is, the third split mask 190 is
aligned so as to overlap the first split mask 140, and the third
gap mask 200 is aligned so as to overlap the first gap mask 150. In
an embodiment, the third split mask 190 may be the same mask as the
above-described split mask 120, and the third gap mask 200 may also
be the same mask as the above-described gap mask 180.
[0127] Subsequently, a third welding portion WE3 is formed by
performing welding on a fifth fixing portion 192 of the third split
mask 190 overlapping the first support part 135a of the mask frame
130, thereby coupling a portion of the third split mask 190 with
the mask frame 130. At the same time, for example, a seventh
welding portion WE7 is formed by performing welding on a sixth
fixing portion 202 of the third gap mask 200 overlapping the first
support part 135a of the mask frame 130, thereby coupling a portion
of the third gap mask 200 with the mask frame 130.
[0128] Then, a fourth welding portion WE4 is formed by performing
welding on the fifth fixing portion 192 of the third split mask 190
overlapping the second side 133b of the mask frame 130, thereby
coupling a portion of the third split mask 190 with the mask frame
130. At the same time, for example, an eighth welding portion WE8
is formed by performing welding on a sixth fixing portion 202 of
the third gap mask 200 overlapping the second side 133b of the mask
frame 130, thereby coupling a portion of the third gap mask 200
with the mask frame 130.
[0129] Subsequently, third cutting TR3 is performed on a portion of
the third split mask 190 overlapping the first support part 135a of
the mask frame 130, for example, between the third welding portion
WE3 of the third split mask 190 and the second welding portion WE2
of the first split mask 140. At the same time, for example, third
cutting TR3 is performed on a portion of the third gap mask 200
overlapping the first support part 135a of the mask frame 130, for
example, between the seventh welding portion WE7 of the third gap
mask 200 and the sixth welding portion WE6 of the first gap mask
180.
[0130] Then, fourth cutting TR4 is performed on the second side of
the third split mask 190 overlapping the second side 133b of the
mask frame 130, for example, between the fourth welding portion WE4
of the third split mask 190 and the second side of the third split
mask 190. At the same time, for example, fourth cutting TR4 is
performed on the second side of the third gap mask 200 overlapping
the second side 133b of the mask frame 130, for example, between
the eighth welding portion WE8 of the third gap mask 200 and the
second side of the third gap mask 200.
[0131] As a result, as shown in FIG. 3, the first split mask 140
and the second split mask 160 made of the third split mask may be
coupled on the mask frame 130. Further, the first gap mask 150 and
the second gap mask 170 made of the third gap mask may be coupled
on the mask frame 130.
[0132] In the above-described embodiment, through four cutting
processes, the split mask 120 may be divided into the first split
mask 140 and the second split mask 160 to be separated from each
other, and the gap mask 180 may be divided into the first gap mask
150 and the second gap mask 170 to be separated from each
other.
[0133] FIG. 13 is a plan view schematically showing a mask assembly
according to another embodiment; and FIG. 14 is a cross-sectional
view schematically showing a structure taken along the line II-II'
of FIG. 13. FIG. 15 is a cross-sectional view schematically showing
a structure according to another embodiment, taken along the line
II-II' of FIG. 13. FIG. 16 is a cross-sectional view schematically
showing a structure according to another embodiment, taken along
the line II-II' of FIG. 13. FIG. 17 is a cross-sectional view
schematically showing a structure taken along the line III-III' of
FIG. 13.
[0134] Referring to FIGS. 13 to 17, the mask assembly 100 according
to an embodiment may include the first split mask 140 and the
second split mask 160 coupled on the mask frame 130. In particular,
the embodiment of FIGS. 13 to 17 has a difference from the
above-described embodiment of FIGS. 3 to 12 in that it further
includes half-etched portions HE1 and HE2, and configurations of
the other portions may be substantially the same or similar. Thus,
a redundant description may be omitted and differences will be
mainly described.
[0135] Referring to FIGS. 13 to 14, the mask assembly 100 according
to an embodiment may include the first split mask 140 and the
second split mask 160 coupled to the mask frame 130. The first
split mask 140 may overlap the first mask opening 132a, a first end
of the first split mask 140 may be coupled to the first side 133a
of the mask frame 130, and a second end of the first split mask 140
may be coupled to the first support part 135a of the mask frame
130. The second split mask 160 may overlap the second mask opening
132b, a first end of the second split mask 160 may be coupled to
the first support part 135a of the mask frame 130, and a second end
of the second split mask 160 may be coupled to the second side 133b
of the mask frame 130.
[0136] The first split mask 140 may include a first half-etched
portion HE1 in the first fixing portion 142 overlapping the first
support part 135a of the mask frame 130. The second split mask 160
may include a second half-etched portion HE2 in the second fixing
portion 162 overlapping the first support part 135a of the mask
frame 130. The first half-etched portion HE1 may be a groove that
is partially etched in the thickness direction of the first split
mask 140, and the second half-etched portion HE2 may be a groove
that is partially etched in the thickness direction of the second
split mask 160.
[0137] The first half-etched portion HE1 and the second half-etched
portion HE2 may serve to balance the volume of each region of the
split masks 140 and 160. In the first split mask 140, the first
deposition pattern portions 144 may be disposed at a central
portion thereof, and thus may have a volume difference from one end
where the first fixing portion 142 is disposed. If there is a
volume difference for each region in the first split mask 140,
deformation such as bending may occur in the first split mask 140
due to the volume difference. Thus, deformation of the first split
mask 140 can be prevented or substantially prevented by forming the
first half-etched portion HE1 on one end of the first split mask
140. Similarly, the second split mask 160 may also include the
second half-etched portion HE2.
[0138] The first half-etched portion HE1 of the first split mask
140 may overlap the first fixing portion 142 of the first split
mask 140, and overlap the first support part 135a of the mask frame
130. In an embodiment, a thickness T1 of the first half-etched
portion HE1 may be approximately 50% of a thickness T2 of the first
split mask 140. In an embodiment, the thickness T1 of the first
half-etched portion HE1 may be 30% to 70% of the thickness T2 of
the first split mask 140.
[0139] Similarly, the second half-etched portion HE2 of the second
split mask 160 may overlap the second fixing portion 162 of the
second split mask 160, and overlap the first support part 135a of
the mask frame 130. In an embodiment, a thickness T3 of the second
half-etched portion HE2 may be approximately 50% of a thickness T4
of the second split mask 160. In an embodiment, the thickness T3 of
the second half-etched portion HE2 may be 30% to 70% of the
thickness T4 of the second split mask 160.
[0140] As illustrated in FIG. 14, the first half-etched portion HE1
may not overlap the second welding portion WE2, and the second
half-etched portion HE2 may not overlap the third welding portion
WE3. However, the present embodiment is not limited thereto. The
first half-etched portion HE1 may overlap the second welding
portion WE2, and the second half-etched portion HE2 may overlap the
third welding portion WE3.
[0141] In an embodiment, the first half-etched portion HE1 may be
formed to have a shape etched from one side of the first split mask
140 toward the center of the first split mask 140, and the second
half-etched portion HE2 may be formed to have a shape etched from
one side of the second split mask 160 toward the center of the
second split mask 160.
[0142] As shown in FIG. 15, in another embodiment, the first
half-etched portion HE1 may be disposed to be spaced apart from one
side of the first split mask 140, and the second half-etched
portion HE2 may be disposed to be spaced apart from one side of the
second split mask 160. In an embodiment, the first half-etched
portion HE1 may not overlap the second welding portion WE2 and may
overlap the first fixing portion 142, and the second half-etched
portion HE2 may not overlap the third welding portion WE3 and may
overlap the second fixing portion 162.
[0143] As shown in FIG. 16, in another embodiment, the first
half-etched portion HE1 may be in direct contact with the first
support part 135a of the mask frame 130, and the second half-etched
portion HE2 may be in direct contact with the first support part
135a of the mask frame 130. In this case, the first half-etched
portion HE1 may overlap the second welding portion WE2 and the
first fixing portion 142, and the second half-etched portion HE2
may overlap the third welding portion WE3 and the second fixing
portion 162. In the present embodiment, since the half-etched
portions HE1 and HE2 are in direct contact with the first support
part 135a, welding may be performed under weak conditions to couple
the split mask to the mask frame 130.
[0144] As illustrated in FIG. 17, in another embodiment, the first
half-etched portions HE1 of the first split mask 140 may be
disposed at both ends of the first split mask 140, respectively.
The first half-etched portion HE1 disposed at one end of the first
split mask 140 may overlap the first side 133a of the mask frame
130 and may overlap the first welding portion WE1. The first
half-etched portion HE1 disposed at the other end of the first
split mask 140 may overlap the first support part 135a of the mask
frame 130 and may overlap the second welding portion WE2 of the
first split mask 140.
[0145] The second half-etched portion HE2 disposed at one end of
the second split mask 160 may overlap the first support part 135a
of the mask frame 130 and may overlap the third welding portion
WE3. The second half-etched portion HE2 disposed at the other end
of the second split mask 160 may overlap the second side 133b of
the mask frame 130 and may overlap the fourth welding portion
WE4.
[0146] As described above, the embodiments shown in FIGS. 13 to 17
may include the half-etched portion in the split mask to prevent or
substantially prevent deformation of the split mask due to a volume
difference.
[0147] FIG. 18 is a plan view schematically showing a mask assembly
according to another embodiment; and FIG. 19 is a cross-sectional
view schematically showing a structure taken along the line IV-IV'
of FIG. 18. FIG. 20 is a cross-sectional view schematically showing
a structure according to another embodiment, taken along the line
IV-IV' of FIG. 18. FIG. 21 is a cross-sectional view schematically
showing a structure taken along the line V-V of FIG. 18.
[0148] Referring to FIGS. 18 to 21, the mask assembly 100 according
to an embodiment may include the first split mask 140 and the
second split mask 160 coupled on the mask frame 130. In particular,
the embodiment of FIGS. 18 to 21 has a difference from the
above-described embodiments of FIGS. 3 to 17 in that it further
includes dummy pattern portions DM1 and DM2, and configurations of
the other portions may be substantially the same or similar. Thus,
a redundant description may be omitted and differences will be
mainly described.
[0149] Referring to FIGS. 18 and 19, the mask assembly 100
according to an embodiment may include the first split mask 140 and
the second split mask 160 coupled to the mask frame 130. The first
split mask 140 may overlap the first mask opening 132a, a first end
of the first split mask 140 may be coupled to the first side 133a
of the mask frame 130, and a second end of the first split mask 140
may be coupled to the first support part 135a of the mask frame
130. The second split mask 160 may overlap the second mask opening
132b, a first end of the second split mask 160 may be coupled to
the first support part 135a of the mask frame 130, and a second end
of the second split mask 160 may be coupled to the second side 133b
of the mask frame 130.
[0150] The first split mask 140 may include a first dummy pattern
portion DM1 in the first fixing portion 142 overlapping the first
support part 135a of the mask frame 130. The second split mask 160
may include a second dummy pattern portion DM2 in the second fixing
portion 162 overlapping the first support part 135a of the mask
frame 130. The first dummy pattern portion DM1 may be a hole
passing through the first split mask 140. The second dummy pattern
portion DM2 may be a hole passing through the second split mask
160.
[0151] The first dummy pattern portion DM1 and the second dummy
pattern portion DM2 may serve to block deformation from extending
to the center of the split masks 140 and 160 due to deformation
such as bending due to a difference in volume of each region of the
split masks 140 and 160. In the first split mask 140, the first
deposition pattern portions 144 may be disposed at a central
portion thereof, and thus may have a volume difference from one end
where the first fixing portion 142 is disposed. If there is a
volume difference for each region in the first split mask 140,
deformation such as bending may occur in the first split mask 140
due to the volume difference. Thus, deformation of the first split
mask 140 can be prevented or substantially prevented from extending
to the central portion thereof by forming the first dummy pattern
portion DM1 at one end of the first split mask 140. Similarly, the
second split mask 160 may also include the second dummy pattern
portion DM2.
[0152] The first dummy pattern portion DM1 of the first split mask
140 may overlap the first fixing portion 142 of the first split
mask 140, and may be disposed between the second welding portion
WE2 and the first deposition pattern portion 144 of the first split
mask 140. The first dummy pattern portion DM1 may overlap the first
support part 135a of the mask frame 130. The position of the first
dummy pattern portion DM1 is not particularly limited as long as it
is disposed between the second welding portion WE2 and the first
deposition pattern portion 144 of the first split mask 140.
[0153] A width W1 of the first dummy pattern portion DM1 may be
smaller than a width W2 between the second welding portion WE2 and
the first deposition pattern portion 144 of the first split mask
140. Therefore, the first dummy pattern portion DM1 may prevent or
substantially prevent bending generated from the second welding
portion WE2 from extending to the first deposition pattern portion
144.
[0154] Similarly, the second dummy pattern portion DM2 of the
second split mask 160 may overlap the second fixing portion 162 of
the second split mask 160, and may be disposed between the third
welding portion WE3 and the second deposition pattern portion 164
of the second split mask 160. The second dummy pattern portion DM2
may overlap the first support part 135a of the mask frame 130. The
position of the second dummy pattern portion DM2 is not
particularly limited as long as it is disposed between the third
welding portion WE3 and the second deposition pattern portion 164
of the second split mask 160.
[0155] A width W3 of the second dummy pattern portion DM2 may be
smaller than a width W4 between the third welding portion WE3 and
the second deposition pattern portion 164 of the second split mask
160. Therefore, the second dummy pattern portion DM2 may prevent or
substantially prevent the bending generated from the third welding
portion WE3 from extending to the second deposition pattern portion
164.
[0156] As shown in FIG. 20, in another embodiment, two or more
first dummy pattern portions DM1 and two or more second dummy
pattern portions DM2 may be disposed. As long as the first dummy
pattern portion DM1 is disposed between the second welding portion
WE2 and the first deposition pattern portion 144 of the first split
mask 140, the first dummy pattern portion DM1 may be provided in
plural, and the number thereof is not particularly limited.
Similarly, as long as the second dummy pattern portion DM2 is
disposed between the third welding portion WE3 and the second
deposition pattern portion 164 of the second split mask 160, the
second dummy pattern portion DM2 may be provided in plural, and the
number thereof is not particularly limited.
[0157] As shown in FIG. 21, in an embodiment, the first dummy
pattern portions DM1 may be disposed at both ends of the first
split mask 140, respectively. The first dummy pattern portion DM1
disposed at one end of the first split mask 140 may overlap the
first side 133a of the mask frame 130 and may not overlap the first
welding portion WE1. The first dummy pattern portion DM1 may be
disposed between the first welding portion WE1 and the first
deposition pattern portion 144 of the first split mask 140. The
first dummy pattern portion DM1 disposed at the other end of the
first split mask 140 may overlap the first support part 135a of the
mask frame 130 and may not overlap the second welding portion WE2
of the first split mask 140. The first dummy pattern portion DM1
may be disposed between the second welding portion WE2 and the
first deposition pattern portion 144 of the first split mask
140.
[0158] Similarly, the second dummy pattern portions DM2 may be
disposed at both ends of the second split mask 160, respectively.
The second dummy pattern portion DM2 disposed at one end of the
second split mask 160 may overlap the first side 133a of the mask
frame 130 and may not overlap the third welding portion WE3. The
second dummy pattern portion DM2 may be disposed between the third
welding portion WE3 and the second deposition pattern portion 164
of the second split mask 160. The second dummy pattern portion DM2
disposed at the other end of the second split mask 160 may overlap
the second side 133b of the mask frame 130 and may not overlap the
fourth welding portion WE4. The second dummy pattern portion DM2
may be disposed between the fourth welding portion WE4 and the
second deposition pattern portion 164 of the second split mask
160.
[0159] As described above, the embodiments illustrated in FIGS. 18
to 21 may include the dummy pattern portion in the split mask to
prevent or substantially prevent deformation of the split mask due
to a volume difference from extending to the deposition pattern
portion.
[0160] FIG. 22 is a view schematically illustrating a deposition
process using a mask assembly according to an embodiment.
[0161] Referring to FIG. 22, a process of depositing an electrode
or an organic light emitting layer of an organic light emitting
display device may be performed in a vacuum chamber 300.
[0162] A deposition source 310 may be disposed at a lower portion
inside the vacuum chamber 300. The deposition source 310 may be,
for example, a crucible as a container in which a deposition
material is contained. The mask assembly 100 according to an
embodiment may be mounted by a support 320 on an upper side inside
the vacuum chamber 300 facing the deposition source 310. A
substrate 330, for example, a substrate 330 for manufacturing an
organic light emitting display device may be disposed on the mask
assembly 100. In an embodiment, the mask assembly 100 and the
substrate 330 may be in direct contact with each other.
[0163] When the deposition material evaporates toward the mask
assembly 100 in the deposition source 310 in the vacuum chamber 300
described above, the deposition material may be deposited in a
pattern shape on a region of the substrate 330 through the
deposition pattern portions 144 and 164, respectively, formed in
the split masks 140 and 160 (see FIG. 3) formed in the mask
assembly 100.
[0164] The mask assembly 100 according to the above-described
embodiments may include the first split mask and the second split
mask to deposit the deposition material on the large-area substrate
330. Further, it is possible to prevent or substantially prevent
deformation of the split mask due to the volume difference for each
region of the split mask by including the half-etched portion.
Further, it is possible to prevent or substantially prevent bending
of the split mask from extending to a central portion thereof due
to the volume difference for each region of the split mask by
including the dummy pattern portion.
[0165] FIG. 23 is a cross-sectional view schematically showing an
organic light emitting display device manufactured using the mask
assembly according to an embodiment.
[0166] FIG. 23 illustrates a top emission type display device in
which light L is emitted in a direction away from a substrate 401
on which a light emitting layer EML is formed. However, the present
disclosure is not limited thereto. For example, the display device
may be of a bottom emission type in which light is emitted in a
direction toward the substrate 401 on which the light emitting
layer EML is formed, or a double-sided emission type in which light
is emitted in both the direction toward the substrate 401 and the
direction away from the substrate 401.
[0167] Referring to FIG. 23, an organic light emitting display
device 400 may include the substrate 401. The substrate 401 may be
an insulating substrate. In an embodiment, the substrate 401 may
include a transparent material. For example, the substrate 401 may
include a transparent insulating material, such as glass, quartz,
or the like. In an embodiment, the substrate 401 may be a rigid
substrate. However, the substrate 401 is not limited thereto. For
example, the substrate 401 may include plastic, such as polyimide
or the like, and may have a flexible property such that it can be
bent, folded, or rolled.
[0168] A buffer layer 405 may be disposed on the substrate 401. The
buffer layer 405 may be disposed on a surface of the substrate 401
to protect a thin film transistor TFT and a light emitting element
EMD from moisture penetrating through the substrate 401 susceptible
to moisture permeation. In an embodiment, the buffer layer 405 may
be formed of a plurality of inorganic layers that are alternately
stacked. For example, the buffer layer 405 may be formed of
multiple layers in which one or more inorganic layers of a silicon
nitride layer, a silicon oxynitride layer, a silicon oxide layer, a
titanium oxide layer, and an aluminum oxide layer are alternately
stacked. In an embodiment, the buffer layer 405 may be omitted.
[0169] The thin film transistor TFT may be disposed as a driving
element on the buffer layer 405. The thin film transistor TFT may
include a semiconductor layer 410, a first insulating layer 421, a
second insulating layer 422, and a gate electrode 430.
[0170] Although FIG. 23 illustrates that the thin film transistor
TFT is formed by a top gate method in which the gate electrode 430
is located above the semiconductor layer 410, the present
disclosure is not limited thereto. For example, the thin film
transistor TFT may be formed by a bottom gate method in which the
gate electrode 430 is located below the semiconductor layer 410, or
a double gate method in which the gate electrodes 430 are located
both above and below the semiconductor layer 410.
[0171] For example, the semiconductor layer 410 of the thin film
transistor TFT may be disposed on the buffer layer 405. In an
embodiment, the semiconductor layer 410 may include polycrystalline
silicon, monocrystalline silicon, low-temperature polycrystalline
silicon, amorphous silicon, or an oxide semiconductor. In an
embodiment, a light blocking layer may be formed between the buffer
layer 405 and the semiconductor layer 410 to block external light
incident on the semiconductor layer 410.
[0172] The first insulating layer 421 may be disposed on the
semiconductor layer 410. In an embodiment, the first insulating
layer 421 may be formed of an inorganic layer, for example, a
silicon nitride layer, a silicon oxynitride layer, a silicon oxide
layer, a titanium oxide layer, or an aluminum oxide layer.
[0173] The gate electrode 430 may be disposed on the first
insulating layer 421. The gate electrode 430 may overlap the
semiconductor layer 410. The gate electrode 430 may be formed as a
single layer or multiple layers made of any of molybdenum (Mo),
aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel
(Ni), neodymium (Nd), and copper (Cu), or an alloy thereof.
[0174] The second insulating layer 422 may be disposed on the gate
electrode 430. In an embodiment, the second insulating layer 422
may be formed of an inorganic layer, for example, a silicon nitride
layer, a silicon oxynitride layer, a silicon oxide layer, a
titanium oxide layer, or an aluminum oxide layer.
[0175] A source electrode 451 (or a drain electrode) and a drain
electrode 452 (or a source electrode) of the thin film transistor
TFT may be disposed on the second insulating layer 422. The source
electrode 451 and the drain electrode 452 may be connected to the
semiconductor layer 410 through contact holes passing through the
second insulating layer 422 and the first insulating layer 421. The
source electrode 451 and the drain electrode 452 may be formed of a
single layer or multiple layers made of a low resistance material,
for example, any of aluminum (Al), gold (Au), and copper (Cu), or
an alloy thereof.
[0176] A third insulating layer 423 may be disposed on the source
electrode 451 and the drain electrode 452. The third insulating
layer 423 may be a passivation layer protecting the thin film
transistor TFT therebelow. In an embodiment, the third insulating
layer 423 may be formed of an inorganic layer, for example, a
silicon nitride layer, a silicon oxynitride layer, a silicon oxide
layer, a titanium oxide layer, or an aluminum oxide layer.
[0177] A via layer VIA may be disposed on the third insulating
layer 423. The via layer VIA may be a planarization layer for
flattening a step due to the thin film transistor TFT. In an
embodiment, the via layer VIA may include an organic insulating
material selected from the group consisting of acrylic resin, epoxy
resin, phenolic resin, polyamide resin, polyimide resin,
unsaturated polyester resin, polyphenylene resin,
polyphenylenesulfide resin, and benzocyclobutene (BCB).
[0178] The light emitting element EMD may be disposed on the via
layer VIA. The light emitting element EMD may include a pixel
electrode PXE, the light emitting layer EML, and a common electrode
CME.
[0179] The pixel electrode PXE may be disposed on the via layer
VIA. The pixel electrode PXE may be a first electrode (e.g., an
anode electrode) of the light emitting element EMD. The pixel
electrode PXE may be connected to the drain electrode 452 (or the
source electrode) of the thin film transistor TFT through a contact
hole passing through the via layer VIA.
[0180] In a top emission type structure that emits light toward the
common electrode CME with respect to the light emitting layer EML,
the pixel electrode PXE may be formed of a single layer of silver
(Ag), molybdenum (Mo), titanium (Ti), copper (Cu), or aluminum
(Al), or may be formed of a metal material having high reflectivity
to have a stacked structure (Ti/Al/Ti) of aluminum and titanium, a
stacked structure (ITO/Ag/ITO) of silver and ITO, an APC alloy, or
a stacked structure (ITO/APC/ITO) of an APC alloy and ITO. The APC
alloy is an alloy of silver (Ag), palladium (Pd) and copper
(Cu).
[0181] As another example, in a bottom emission type structure that
emits light toward the pixel electrode PXE with respect to the
light emitting layer EML, the pixel electrode PXE may be formed of
a transparent metal material (transparent conductive material,
TCO), such as indium tin oxide (ITO) or indium zinc oxide (IZO),
capable of transmitting light therethrough, or a semi-transmissive
metal material (semi-transmissive conductive material), such as
magnesium (Mg), silver (Ag), or an alloy of magnesium (Mg) and
silver (Ag). In this case, when the pixel electrode PXE is formed
of a semi-transmissive metal material, the light emission
efficiency can be increased due to a micro-cavity effect.
[0182] A pixel defining layer PDL may be disposed on the pixel
electrode PXE. The pixel defining layer PDL is disposed on the
pixel electrode PXE and may include an opening to expose the pixel
electrode PXE. In an embodiment, the pixel defining layer PDL may
include an organic insulating material selected from the group
consisting of acrylic resin, epoxy resin, phenolic resin, polyamide
resin, polyimide resin, unsaturated polyester resin, polyphenylene
resin, polyphenylenesulfide resin, and benzocyclobutene (BCB).
[0183] The light emitting layer EML may be disposed on the pixel
electrode PXE exposed by the pixel defining layer PDL. The light
emitting layer EML may include an organic material layer. The
organic material layer of the light emitting layer EML may include
an organic light emitting layer, and may further include a hole
injecting/transporting layer and/or an electron
injecting/transporting layer. In an embodiment, the light emitting
layer EML may have a tandem structure in which a plurality of
organic light emitting layers are superposed in the thickness
direction and a charge generation layer is disposed between the
organic light emitting layers. The respective organic light
emitting layers superposed may emit light of a same wavelength, or
may emit light of different wavelengths. At least some of the
layers may be separate from the same layer of neighboring
pixels.
[0184] The common electrode CME may be disposed on the light
emitting layer EML. The common electrode CME may be a second
electrode (e.g., a cathode electrode) of the light emitting element
EMD. The common electrode CME may be formed commonly to the pixels.
In an embodiment, in the top emission type structure, the common
electrode CME may be formed of a transparent conductive material
(TCO), such as ITO or IZO, capable of transmitting light or a
semi-transmissive conductive material, such as magnesium (Mg),
silver (Ag), or an alloy of magnesium (Mg) and silver (Ag). When
the common electrode CME is formed of a semi-transmissive
conductive material, the light emission efficiency can be increased
due to a micro-cavity effect.
[0185] In the bottom emission type structure, the common electrode
CME may be formed of a single layer of aluminum (Al), molybdenum
(Mo), titanium (Ti), copper (Cu), or silver (Ag), or may be formed
of a metal material having high reflectivity to have a stacked
structure (Ti/Al/Ti) of aluminum and titanium, a stacked structure
(ITO/Ag/ITO) of silver and ITO, an APC alloy, or a stacked
structure (ITO/APC/ITO) of an APC alloy and ITO.
[0186] While some example embodiments of the present invention have
been described herein, those skilled in the art will appreciate
that many variations and modifications may be made to the described
embodiments without substantially departing from the principles of
the present invention. Therefore, the disclosed example embodiments
of the invention are used in a generic and descriptive sense and
not for purposes of limitation.
* * * * *