U.S. patent application number 16/380602 was filed with the patent office on 2020-03-19 for display substrate, manufacturing method thereof, and display device.
The applicant listed for this patent is BOE Technology Group Co., Ltd.. Invention is credited to Ying Cui.
Application Number | 20200091254 16/380602 |
Document ID | / |
Family ID | 65180835 |
Filed Date | 2020-03-19 |
United States Patent
Application |
20200091254 |
Kind Code |
A1 |
Cui; Ying |
March 19, 2020 |
Display substrate, manufacturing method thereof, and display
device
Abstract
Embodiments of the present application provide a display
substrate comprising a plurality of first banks distributed in a
first direction and a plurality of second banks distributed in a
second direction. Two adjacent first banks define a group of
sub-pixel units of the display substrate, and two adjacent second
banks define one sub-pixel unit. The first bank has a height
greater than a height of the second bank. Embodiments of the
present application also disclose a manufacturing method of a
display substrate and a display device.
Inventors: |
Cui; Ying; (Beijing,
CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BOE Technology Group Co., Ltd. |
Beijing |
|
CN |
|
|
Family ID: |
65180835 |
Appl. No.: |
16/380602 |
Filed: |
April 10, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 27/3283 20130101;
H01L 51/0005 20130101; H01L 27/3246 20130101; H01L 2227/323
20130101; H01L 51/56 20130101 |
International
Class: |
H01L 27/32 20060101
H01L027/32; H01L 51/00 20060101 H01L051/00; H01L 51/56 20060101
H01L051/56 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 17, 2018 |
CN |
201811079246.7 |
Claims
1. A display substrate comprising: a base substrate; and a
plurality of first banks distributed in a first direction and a
plurality of second banks distributed in a second direction on the
base substrate, two adjacent first banks defining a group of
sub-pixel units of the display substrate, the second banks being
disposed between two adjacent first banks, and two adjacent second
banks defining one of the sub-pixel units, wherein the first bank
has a height greater than a height of the second bank.
2. The display substrate according to claim 1, wherein the second
bank has a height less than a height of a liquid surface of a
solution applied for forming a film layer of the sub-pixel units by
a solution process.
3. The display substrate according to claim 2, wherein a top
surface of the second bank has a property of being phobic to the
solution.
4. The display substrate according to claim 2, wherein a top
surface of the first bank has a property of being phobic to the
solution.
5. The display substrate according to claim 1, wherein all of the
first banks have the same height.
6. The display substrate according to claim 1, wherein the height
of the first bank is in a range of from 1 .mu.m to 3 .mu.m.
7. The display substrate according to claim 1, wherein all of the
second banks have the same height.
8. The display substrate according to claim 1, wherein the height
of the second bank is in a range of from 100 nm to 500 nm.
9. The display substrate according to claim 1, wherein the display
substrate further comprises end banks disposed between two adjacent
first banks, wherein the end banks are disposed in the same
direction as the second banks but on outermost sides of the second
banks.
10. The display substrate according to claim 9, wherein the end
banks have a height greater than the height of the second bank.
11. The display substrate according to claim 1, wherein all of the
first banks have the same width in a range of from 10 .mu.m to 30
.mu.m in the first direction, and the first banks have a strip
shape.
12. The display substrate according to claim 1, wherein all of the
second banks have the same width in a range of from 5 .mu.m to 20
.mu.m in the second direction, and the second banks have a strip
shape.
13. A display device comprising the display substrate according to
claim 1.
14. The display device according to claim 13, wherein the display
device includes polymer light emitting diode (PLED).
15. A manufacturing method of a display substrate, comprising:
fabricating a plurality of first banks in a first direction on a
base substrate, two adjacent first banks defining a group of
sub-pixel units of the display substrate; and fabricating a
plurality of second banks in a second direction between each pair
of two adjacent first banks, two adjacent second banks defining one
of the sub-pixel units, wherein the first bank has a height greater
than a height of the second bank.
16. The manufacturing method according to claim 15, wherein the
manufacturing method further comprises fabricating end banks
between two adjacent first banks, wherein the end banks are
disposed in the same direction as the second banks but on outermost
sides of the second banks.
17. The manufacturing method according to claim 15, wherein after
fabricating the second banks, the method further comprises:
fabricating a film layer by a solution process on the base
substrate on which the first banks and the second banks are
fabricated, a liquid surface of the applied solution having a
height between the height of the first bank and the height of the
second bank.
18. The manufacturing method according to claim 17, wherein after
fabricating the plurality of second banks in the second direction
between each pair of two adjacent first banks, and before
fabricating the film layer by a solution process on the base
substrate on which the first banks and the second banks are
fabricated, the method further comprises: fabricating a film having
a property of being phobic to the solution on a top surface of the
second bank.
19. The manufacturing method according to claim 17, wherein the
fabricating the film layer by a solution process on the base
substrate on which the first banks and the second banks are
fabricated comprises: fabricating the film layer by an ink jet
printing process on the base substrate on which the first banks and
the second banks are fabricated.
20. The manufacturing method according to claim 17, wherein after
fabricating the film layer by a solution process on the base
substrate on which the first banks and the second banks are
fabricated, the method further comprises: subjecting the film layer
fabricated to a drying treatment, such that the treated film layer
has a height less than the height of the second bank.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims a priority benefit of Chinese
Patent Application No. 201811079246.7, filed on Sep. 17, 2018, the
entire contents thereof being incorporated herein by reference.
TECHNICAL FIELD
[0002] The present disclosure relates to the technical field of
display, and particularly to a display substrate, a manufacturing
method thereof, and a display device.
BACKGROUND
[0003] In various film forming technologies, solution film forming
technologies attract more and more attention. So-called solution
film forming procedure is a process comprising treating required
materials, for example, breaking them into nanoscale fine
particles, subsequently dissolving them in a solvent, and then
using another instrument to deposit the solution on a surface of a
substrate, so as to form a required film on the surface of the
substrate after the solvent is evaporated.
[0004] Ink jet printing, an important one of the solution film
forming technologies, is widely used in manufacturing polymer light
emitting diode (PLED), liquid crystal display (LCD) color filter,
organic thin film transistor, metal electrode, three dimension
separating wall and the like, due to its advantages of easy
operation, low cost, simple process, easy achievement of large size
and so on.
[0005] With increasingly higher demand for the resolution of a
display device at present, a stricter requirement is proposed for
the film forming homogeneity within pixels formed by technologies
such as ink jet printing.
SUMMARY
[0006] The present disclosure provides a display substrate, a
manufacturing method thereof, and a display device.
[0007] In one aspect, the present disclosure provides a display
substrate comprising: a base substrate; and a plurality of first
banks distributed in a first direction and a plurality of second
banks distributed in a second direction on the base substrate, two
adjacent first banks defining a group of sub-pixel units of the
display substrate, the second banks being disposed between two
adjacent first banks, and two adjacent second banks defining one of
the sub-pixel units, wherein the first bank has a height greater
than a height of the second bank.
[0008] In some embodiments, the second bank has a height less than
a height of a liquid surface of a solution applied for forming a
film layer of the sub-pixel units by a solution process.
[0009] In some embodiments, a top surface of the second bank has a
property of being phobic to the solution (or being repellent to the
solution).
[0010] In some embodiments, a top surface of the first bank has a
property of being phobic to the solution.
[0011] In some embodiments, all of the first banks have the same
height.
[0012] In some embodiments, the height of the first bank is in a
range of from 1 .mu.m to 3 .mu.m.
[0013] In some embodiments, all of the second banks have the same
height.
[0014] In some embodiments, the height of the second bank is in a
range of from 100 nm to 500 nm.
[0015] In some embodiments, the display substrate further comprises
end banks disposed between two adjacent first banks, wherein the
end banks are disposed in the same direction as the second banks
but on outermost sides of the second banks.
[0016] In some embodiments, the end banks have a height greater
than a height of the second bank.
[0017] In some embodiments, all of the first banks have the same
width in a range of from 10 .mu.m to 30 .mu.m in the first
direction, and the first banks have a strip shape.
[0018] In some embodiments, all of the second banks have the same
width in a range of from 5 .mu.m to 20 .mu.m in the second
direction, and the second banks have a strip shape.
[0019] In another aspect, the present disclosure provides a display
device comprising the above-mentioned display substrate.
[0020] In some embodiments, the display device includes polymer
light emitting diode (PLED).
[0021] In still another aspect, the present disclosure provides a
manufacturing method of a display substrate, comprising:
fabricating a plurality of first banks in a first direction on a
base substrate, two adjacent first banks defining a group of
sub-pixel units of the display substrate; and fabricating a
plurality of second banks in a second direction between each pair
of two adjacent first banks, two adjacent second banks defining one
of the sub-pixel units, wherein the first bank has a height greater
than a height of the second bank.
[0022] In some embodiments, the manufacturing method further
comprises fabricating end banks between two adjacent first banks,
wherein the end banks are disposed in the same direction as the
second banks but on outermost sides of the second banks.
[0023] In some embodiments, after fabricating the second banks, the
method further comprises:
[0024] fabricating a film layer by a solution process on the base
substrate on which the first banks and the second banks are
fabricated, a liquid surface of the applied solution having a
height between the height of the first bank and the height of the
second bank.
[0025] In some embodiments, after fabricating the plurality of
second banks in the second direction between each pair of two
adjacent first banks, and before fabricating the film layer by a
solution process on the base substrate on which the first banks and
the second banks are fabricated, the method further comprises:
[0026] fabricating a film having a property of being phobic to the
solution on a top surface of the second bank.
[0027] In some embodiments, the fabricating the film layer by a
solution process on the base substrate on which the first banks and
the second banks are fabricated comprises:
[0028] fabricating the film layer by an ink jet printing process on
the base substrate on which the first banks and the second banks
are fabricated.
[0029] In some embodiments, after fabricating the film layer by a
solution process on the base substrate on which the first banks and
the second banks are fabricated, the method further comprises:
subjecting the film layer fabricated to a drying treatment, such
that the treated film layer has a height less than the height of
the second bank.
BRIEF DESCRIPTION OF DRAWINGS
[0030] The above and/or additional aspects and advantages of the
present disclosure will become apparent and easily understood from
the description of the embodiments with reference to the drawings
below, in which:
[0031] FIG. 1 is a flow chart of a manufacturing method of a
display substrate according to an embodiment of the present
disclosure;
[0032] FIG. 2 is a schematic structure diagram of a display
substrate according to an embodiment of the present disclosure;
and
[0033] FIG. 3 is a schematic structure diagram of a display
substrate according to an embodiment of the present disclosure when
a film layer is fabricated by a solution process.
DETAILED DESCRIPTION
[0034] The embodiments of the present disclosure will be described
in detail below. The examples of the embodiments are shown in the
drawings, throughout which identical or similar reference numbers
indicate identical or similar elements or elements having identical
or similar functions. The embodiments described below with
reference to the drawings are exemplary, and are only intended to
illustrate the present invention, but cannot be interpreted to
limit the present invention.
[0035] It can be appreciated by those skilled in the art that the
singular forms "a", "an", "said" and "the" as used herein may
include plural references, unless specifically indicated otherwise.
It should be further appreciated that the wording
"comprise/comprising" as used in the description of the present
disclosure means that the recited feature, integer, step,
operation, element and/or component are present, but the presence
or addition of one or more additional features, integers, steps,
operations, elements, components and/or a combination thereof is
not excluded. It should be appreciated that when an element is said
to be "connected" to another element, it may be directly connected
to another element, or there may be an intermediate element. In
addition, the term "connecting/connection" as used herein may
include wireless connection. The wording "and/or" as used herein is
intended to include all or any one member of one or more associated
items as listed, and all combinations thereof.
[0036] It can be appreciated by those skilled in the art that all
terms as used herein (including technical terms and scientific
terms) have the same meanings as commonly understood by one of
ordinary skill in the art to which the present invention pertains,
unless otherwise defined. It should also be appreciated that the
terms as defined in general dictionaries should be understood as
having the same meanings as those in the context of prior art, and
will not be interpreted with an idealized or too formal meaning
unless specifically defined herein.
[0037] The applicant has discovered that in the case of printing
ink in sub-pixels by an ink jet printing technology, the printed
inks in the sub-pixel units are separated from each other. In order
to obtain homogeneous film forming between pixels, it is required
to continuously adjust the volume difference between the nozzles of
the sprayer. However, the degree of the adjustment is limited, and
thus it is difficult to enable the volumes injected from the
nozzles to be completely consistent with each other. As such,
difference in film forming between the pixels will occur during
drying, leading to inhomogeneous light emitting between
sub-pixels.
[0038] Therefore, the applicant provides a film forming method for
a film layer, in order to at least partially alleviate or eliminate
the problem of inhomogeneous film forming within the sub-pixel
regions.
[0039] FIG. 1 shows a flow chart of a manufacturing method of a
display substrate according to an embodiment of the present
disclosure. The method comprises the following steps.
[0040] S101: Fabricating a plurality of first banks in a first
direction on a base substrate, two adjacent first banks defining a
group of sub-pixel units of the display substrate.
[0041] Here, in the above S101, the first direction may be a row
direction from a front view direction of the base substrate, and a
group of sub-pixel units may be a column of sub-pixel units in the
front view direction of the base substrate. That is, in an
embodiment of the present disclosure, a plurality of first banks
are fabricated in the row direction on the base substrate, and a
region between two adjacent first banks corresponds to a column of
sub-pixel units of the display substrate (i.e., two adjacent first
banks define a column of sub-pixel units).
[0042] S102: Fabricating a plurality of second banks in a second
direction between each pair of two adjacent first banks, two
adjacent second banks defining one of the sub-pixel units, wherein
the first bank has a height greater than a height of the second
bank.
[0043] Here, in the above S102, the second direction may be a
column direction from a front view direction of the base substrate.
In an embodiment of the present disclosure, a plurality of second
banks are fabricated in the column direction between each pair of
two adjacent first banks, and a region between two adjacent second
banks corresponds to one sub-pixel unit (i.e., two adjacent second
banks define one sub-pixel unit).
[0044] In a particular embodiment, the manufacturing method further
comprises a step of fabricating end banks between two adjacent
first banks, wherein the end banks are disposed in the same
direction as the second banks but on outermost sides of the second
banks. The end bank may have the same height as the height of the
first bank.
[0045] In a particular embodiment, after the above S102, the
manufacturing method of a display substrate further comprises:
fabricating a film layer by a solution process on the base
substrate on which the first banks and the second banks are
fabricated, a liquid surface of the applied solution having a
height between the height of the first bank and the height of the
second bank.
[0046] In the embodiments of the present disclosure, by fabricating
a plurality of first banks having a larger height and a plurality
of second banks having a smaller height on the base substrate, two
adjacent first banks define a group of sub-pixel units of the
display substrate, and two adjacent second banks define one
sub-pixel unit. In fabricating a film layer by a solution process,
when the applied solution has a liquid surface higher than the
second bank, the solution can flow between the sub-pixel units
across the second banks with a smaller height, such that there is
an equal volume of solution in each sub-pixel unit. As such, a film
layer with uniform thickness will be formed in each sub-pixel unit,
overcoming the problem of inhomogeneous thickness of the film
layers in the sub-pixel units, and in turn improving the
homogeneity of light emitting in the sub-pixel units.
[0047] Further, in order to allow the formed films in different
sub-pixel units to be separated from each other after subsequent
drying, so as to avoid the interference between different sub-pixel
units and avoid the retention of solution, the method may further
comprise, after fabricating the plurality of second banks in the
column direction between each pair of two adjacent first banks and
before fabricating the film layer by a solution process on the base
substrate on which the first banks and the second banks are
fabricated: fabricating a film having a property of being phobic to
the solution on a top surface (a surface on a side away from the
substrate) of the second bank.
[0048] Optionally, in the embodiments of the present disclosure, a
top surface of the first bank may also have a property of being
phobic to the solution, such that the solution in each column of
the sub-pixel units will not overflow during film forming, avoiding
the interference between different columns of the sub-pixel
units.
[0049] In particular, with respect to the manufacturing method of
the first banks, fabricating the plurality of first banks in the
row direction on the base substrate may comprise: fabricating the
plurality of first banks in the row direction on the base substrate
by a patterning process.
[0050] In particular, with respect to the manufacturing method of
the second banks, fabricating the plurality of second banks in the
column direction between each pair of two adjacent first banks may
comprise: fabricating the plurality of second banks in the column
direction between each pair of two adjacent first banks by a
patterning process or a deposition process. The patterning process
in the embodiments of the present disclosure comprises some or all
of applying, exposing, developing and etching procedures.
[0051] In the embodiments of the present disclosure, a film layer
may be fabricated by ink jet printing on the base substrate on
which the first banks and the second banks are fabricated, because
ink jet printing is an important one of solution film forming
technologies, and has advantages of easy operation, low cost,
simple process, easy achievement of large size, and the like.
However, for those skilled in the art, the film layer may also be
fabricated by another solution film forming process on the base
substrate with the first banks and the second banks in embodiments
of the present disclosure.
[0052] In order to more rapidly form a film layer, the method of
the embodiments of the present disclosure further comprises, after
fabricating the film layer by a solution process on the base
substrate on which the first banks and the second banks are
fabricated: subjecting the film layer fabricated to a drying
treatment, such that the treated film layer has a height less than
the height of the second bank, thereby finally forming film layers
with uniform thickness in the sub-pixel units. Of course, during
practical production, the drying treatment may not be performed,
and the film layer fabricated is naturally air dried, which,
however, will extend the production time.
[0053] The film forming method of the embodiments of the present
disclosure will be explained below by describing each step in
detail.
[0054] As shown in FIG. 2, firstly, a plurality of first banks 1
are fabricated in a row direction (such as a horizontal direction)
on a base substrate 10, wherein two adjacent first banks 1 define a
column of sub-pixel units; and then, a plurality of second banks 2
are fabricated in a column direction (such as a vertical direction)
between each pair of two adjacent first banks 1 on the base
substrate 10, wherein two adjacent second banks 2 define one
sub-pixel unit 3.
[0055] It should be noted that an end bank 2' is disposed at an end
of each column of sub-pixel units (two end banks at both ends),
wherein a height of the end bank 2' is greater than a height of the
second bank 2, and may be equal to or greater than a height of the
first bank 1. In addition, a top surface of end bank 2' may have a
property of being phobic to the solution, so as to prevent the
solution from overflowing from the end of the column during film
forming.
[0056] Next, as shown in FIG. 2 and FIG. 3, the solution prepared
is applied, e.g. by ink jet printing, into the sub-pixel units. At
this time, because the height of the liquid surface of the solution
4 is higher than the height of the second bank 2, the solution
injected in each column of the sub-pixel units 3 can flow freely in
the sub-pixel units. Because the top surface of the end bank 2' has
a property of being phobic to the solution, overflowing of the
solution 4 in each column of the sub-pixel units from the end of
the column is avoided. In addition, because the top surface of the
first bank 1 has a property of being phobic to the solution, the
solution 4 in each column of the sub-pixel units will not overflow
into an adjacent column, avoiding the interference between
different columns of sub-pixel units.
[0057] In practical implementations, if a first column of sub-pixel
units are red sub-pixel units displaying red color, a second column
of sub-pixel units are green sub-pixel units displaying green
color, and a third column of sub-pixel units are blue sub-pixel
units displaying blue color. In the embodiments of the present
disclosure, red ink may be injected into a region corresponding to
the first column of sub-pixel units, green ink may be injected into
a region corresponding to the second column of sub-pixel units, and
blue ink may be injected into a region corresponding to the third
column of sub-pixel units; in addition, the second banks 2 are
configured such that ink can be in fluid communication with each
other within each column of sub-pixel units, and the first banks 1
are configured such that ink in each column does not overflow.
[0058] Finally, after each sub-pixel unit is filled with the
solution, the film layer formed is subjected to a drying treatment
in particular embodiments of the present disclosure. Because the
(top) surface of each second bank is fabricated to have a property
of being phobic to the solution, as such, during drying, separated
film layers with uniform volume are formed in respective sub-pixel
units. Because the separated film layers with uniform volume are
formed in respective sub-pixel units previously, the homogeneity of
the film layer(s) subsequently formed, e.g. by chemical vapor
deposition (CVD), can also be improved, thereby improving the
homogeneity of light emitting of the sub-pixel units.
[0059] In the embodiments of the present disclosure, the sub-pixel
units in each column are separated from each other by the second
banks, such that when ink is printed in the sub-pixel units by ink
jet printing, the sub-pixel units are in communication with each
other, that is, the ink is in fluid communication in each column of
sub-pixel units, and is thus uniformly distributed in each
sub-pixel unit within this column, as a result, the problem of ink
volume difference in different sub-pixel units due to different
nozzle volumes is eliminated.
[0060] The film forming method for a film layer provided by the
embodiments of the present disclosure can significantly ameliorate
the problem of inhomogeneous film thickness between high resolution
printed device pixels, thereby improving the homogeneity of light
emitting of the pixels, and in turn improving the light emitting
quality and lifetime of the device.
[0061] The present disclosure also discloses a display substrate,
as shown in FIG. 2, comprising: a base substrate 10; and a
plurality of first banks 1 distributed in a first direction and a
plurality of second banks 2 distributed in a second direction on
the base substrate 10, wherein two adjacent first banks 1 define a
group of sub-pixel units 3 of the display substrate, the second
banks 2 are disposed between two adjacent first banks 1, and two
adjacent second banks 2 define one sub-pixel unit 3. The first bank
1 has a height greater than a height of the second bank 2.
[0062] In particular, the second bank 2 has a height less than a
height of a liquid surface of a solution applied for forming a film
layer by a solution process on the base substrate on which the
first banks 1 and the second banks 2 are fabricated.
[0063] In a particular embodiment, the first direction is a row
direction and the second direction is a column direction when the
base substrate is viewed from a front view direction. In the
embodiments of the present disclosure, the group of sub-pixel units
3 is a column of sub-pixel units 3.
[0064] In a particular embodiment, the display substrate may be an
array substrate in a liquid crystal display panel, a color film
substrate, or a backplane in an organic electroluminescent display
panel.
[0065] According to the requirements for practical demand and
product, the sub-pixel units 3 may have different shapes. As shown
in FIG. 2, because the arrangement direction of the first banks 1
is perpendicular to the arrangement direction of the second banks
2, the sub-pixel units 3 have a rectangular shape. However, for
those skilled in the art, the sub-pixel units 3 may have other
regular or irregular shapes.
[0066] By fabricating a plurality of first banks 1 and second banks
2 having different heights on the base substrate, a region between
two adjacent second banks 2 corresponds to one sub-pixel unit 3.
When a solution has a liquid surface higher than the second bank 2,
the solution can flow within each column of sub-pixel units 3
across the second banks 2 with a smaller height, such that there is
an equal volume of solution in each sub-pixel unit 3 of each column
of sub-pixel units 3. As such, a film layer with uniform thickness
will be formed in each sub-pixel unit 3, overcoming the problem of
inhomogeneous thickness of the film layers in the sub-pixel units
3.
[0067] Further, in the embodiments of the present application, in
order to allow the film layers in the sub-pixel units to be
separated in subsequent drying, and to avoid the interference
between the sub-pixel units, the surface of the second bank 2 is
provided with a property of being phobic to the solution.
[0068] Preferably, in the embodiments of the present disclosure,
the surface of the first bank has a property of being phobic to the
solution, such that film forming in each column of sub-pixel units
is separated, avoiding the interference between different columns
of sub-pixel units.
[0069] In practical implementations, the material of the first bank
1 comprises an organic material, for example, a polyimide material
may be selected as the material of the first bank 1; and the
material of the second bank 2 may be an organic material or an
inorganic material, for example, a silica material may be selected
as the material of the second bank 2. However, for those skilled in
the art, other materials may also be selected for the first bank 1
and the second bank 2.
[0070] In the embodiments of the present disclosure, because the
material of the first bank 1 comprises an organic material, the
first bank is typically formed on the base substrate by applying,
exposing, and developing. When the material of the second bank 2
comprises an inorganic material, the second bank is typically
formed on the base substrate by a process such as deposition.
[0071] In a preferred embodiment, all of the first banks 1 have the
same height in a range of from 1 .mu.m to 3 .mu.m, for example, 1.5
.mu.m. As such, uniform first banks are fabricated on the base
substrate, and thus solution overflowing can be better prevented in
subsequent fabrication of a film layer by a solution process.
[0072] In another preferred embodiment, all of the second banks 2
have the same height in a range of from 100 nm to 500 nm, for
example, 300 nm. As such, uniform second banks are fabricated on
the base substrate, and thus it is better for allowing an equal
volume of solution in each sub-pixel unit of each column of
sub-pixel units in subsequent fabrication of a film layer by a
solution process, thereby forming a film layer with uniform
thickness in each sub-pixel unit.
[0073] Further, in particular embodiments of the present
disclosure, all of the first banks 1 have the same width in a range
of from 10 .mu.m to 30 .mu.m, for example 17 .mu.m, in the row
direction. All of the second banks 2 have the same width of 5 .mu.m
to 20 .mu.m, for example 10 .mu.m, in the column direction. Such
width configuration for the first banks 1 and the second banks 2
will have no disadvantageous influence on the display area of the
display substrate.
[0074] In order to allow the film forming method for a film layer
to have the advantages of simple operation and easy mass
production, thereby significantly reducing the production cost, in
the embodiments of the present disclosure, the first banks 1 are
configured to have a strip shape, and the second banks 2 are
configured to have a strip shape.
[0075] The embodiments of the present disclosure further disclose a
display device comprising the above display substrate. The
advantages of the display device are the same as those of the above
display substrate, and thus will not be reiterated here. The
display device in the embodiments of the present disclosure may
include polymer light emitting diode (PLED).
[0076] The advantageous effects produced by the embodiments of the
present disclosure may comprise at least one of the following
effects.
[0077] 1. In the embodiments of the present disclosure, by
fabricating a plurality of first banks and second banks with
different heights on the base substrate, two adjacent first banks
define a group of sub-pixel units of the display substrate, and two
adjacent second banks define one sub-pixel unit. In fabricating a
film layer, when a liquid surface of a solution is higher than the
height of the second bank, the solution can flow between the
sub-pixel units across the second banks with a smaller height, such
that there is an equal volume of solution in each sub-pixel unit.
As such, a film layer with uniform thickness will be formed in each
sub-pixel unit, overcoming the problem of inhomogeneous thickness
of the film layers in the sub-pixel units, and in turn improving
the homogeneity of light emitting in the sub-pixel units.
[0078] 2. Because the (top) surface of the second bank has a
property of being phobic to the solution, the films formed in
respective sub-pixel units, after subsequent drying, are separated,
avoiding the interference between the sub-pixel units.
[0079] 3. Because the (top) surface of the first bank has a
property of being phobic to the solution, the solution in each
column of the sub-pixel units will not overflow during film
forming, avoiding the interference between different columns of
sub-pixel units.
[0080] 4. The film forming method for a film layer according to the
embodiments of the present disclosure has the advantages of simple
operation and easy mass production, significantly reducing the
production cost.
[0081] The above description is only a part of the embodiments of
the present invention. It should be noted that some modifications
and variations can be made by one of ordinary skill in the art
without departing from the principle of the present invention.
These modifications and variations should also be regarded as
falling into the protection scope of the present invention.
* * * * *