U.S. patent application number 15/881799 was filed with the patent office on 2019-06-06 for micro lighting device.
The applicant listed for this patent is ACER INCORPORATED. Invention is credited to Chih-Chiang Chen, Jui-Chieh Hsiang.
Application Number | 20190172760 15/881799 |
Document ID | / |
Family ID | 66590642 |
Filed Date | 2019-06-06 |
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United States Patent
Application |
20190172760 |
Kind Code |
A1 |
Hsiang; Jui-Chieh ; et
al. |
June 6, 2019 |
MICRO LIGHTING DEVICE
Abstract
A micro lighting device includes a source line, a ground line, a
main LED, and a redundant LED. The main LED includes a first
electrode and a second electrode, and the redundant LED includes a
third electrode and a fourth electrode. When the main LED is able
to light up, the first electrode is electrically connected to the
source line, the second electrode is electrically connected to the
ground line, and at least one of the third electrode and the fourth
electrode is electrically isolated from both the source line and
the ground line. When the main LED is unable to light up, at least
one of the first electrode and the second electrode is electrically
isolated from both the source line and the ground line, the third
electrode is electrically connected to the source line, and the
fourth electrode is electrically connected to the ground line.
Inventors: |
Hsiang; Jui-Chieh; (New
Taipei City, TW) ; Chen; Chih-Chiang; (New Taipei
City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ACER INCORPORATED |
New Taipei City |
|
TW |
|
|
Family ID: |
66590642 |
Appl. No.: |
15/881799 |
Filed: |
January 28, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 22/22 20130101;
H01L 33/62 20130101; H01L 25/0756 20130101; H01L 25/0753
20130101 |
International
Class: |
H01L 21/66 20060101
H01L021/66; H01L 25/075 20060101 H01L025/075; H01L 33/62 20060101
H01L033/62 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 5, 2017 |
TW |
106142619 |
Claims
1. A micro lighting device, comprising: a source line; a ground
line; a main luminescent device comprising a first electrode and a
second electrode, wherein: the first electrode is electrically
connected to the source line and the second electrode is
electrically connected to the ground line when the main luminescent
device is able to light up; at least one of the first electrode and
the second electrode is electrically isolated from both the source
line and the ground line when the main luminescent device is unable
to light up; and a redundant luminescent device comprising a third
electrode and a fourth electrode, wherein: at least one of the
third electrode and the fourth electrode is electrically isolated
from both the source line and the ground line when the main
luminescent device is able to light up; and the third electrode is
electrically connected to the source line and the fourth electrode
is electrically connected to the ground line when the main
luminescent device is unable to light up.
2. The micro lighting device of claim 1, wherein: the main
luminescent device further comprises: a first semiconductor layer
of a first doping type, wherein the first electrode is disposed on
the first semiconductor layer; a first luminescent layer disposed
on the first semiconductor layer; and a second semiconductor layer
of a second doping type disposed on the first luminescent layer,
wherein the second electrode is disposed on the second
semiconductor layer; the redundant luminescent device further
comprises: a third semiconductor layer of the first doping type,
wherein the third electrode is disposed on the third semiconductor
layer; a second luminescent layer disposed on the third
semiconductor layer; and a fourth semiconductor layer of the second
doping type disposed on the second luminescent layer, wherein the
fourth electrode is disposed on the fourth semiconductor layer; and
the main luminescent device and the redundant luminescent device
are fabricated and then transferred to be disposed on a
substrate.
3. The micro lighting device of claim 1, wherein the main
luminescent device and the redundant luminescent device are micro
light emitting diodes (LEDs).
4. A micro lighting device, comprising: a source line; a ground
line; a main luminescent device comprising a first electrode and a
second electrode, wherein: the first electrode is electrically
connected to the source line and the second electrode is
electrically connected to the ground line when the main luminescent
device is able to light up; both the first electrode and the second
electrode are electrically isolated from both the source line and
the ground line when the main luminescent device is unable to light
up; a redundant luminescent device comprising a third electrode and
a fourth electrode and arranged to be disposed on the main
luminescent device when the main luminescent device is unable to
light up; and a conductive material for electrically connecting the
third electrode to the source line and for electrically connecting
the fourth electrode to the ground line.
5. The micro lighting device of claim 4, wherein: the main
luminescent device further comprises: a first semiconductor layer
of a first doping type, wherein the first electrode is disposed on
the first semiconductor layer; a first luminescent layer disposed
on the first semiconductor layer; and a second semiconductor layer
of a second doping type disposed on the first luminescent layer,
wherein the second electrode is disposed on the second
semiconductor layer; the redundant luminescent device further
comprises: a third semiconductor layer of the first doping type,
wherein the third electrode is disposed on the third semiconductor
layer; a second luminescent layer disposed on the third
semiconductor layer; and a fourth semiconductor layer of the second
doping type disposed on the second luminescent layer, wherein the
fourth electrode is disposed on the fourth semiconductor layer; the
main luminescent device is fabricated and then transferred to be
disposed on a substrate; and the redundant luminescent device is
fabricated and then transferred to be disposed on the main
luminescent device.
6. The micro lighting device of claim 4, wherein the main
luminescent device and the redundant luminescent device are micro
LEDs.
7. A method of manufacturing and repairing micro lighting device,
comprising: fabricating a main luminescent device which includes a
first electrode and a second electrode and then transferring the
main luminescent device to be disposed on a substrate; fabricating
a redundant luminescent device which includes a third electrode and
a fourth electrode and then transferring the redundant luminescent
device to be disposed on the substrate; electrically connecting the
first electrode to a source line, electrically connecting the
second electrode to a ground line, and electrically isolating at
least one of the third electrode and the fourth electrode from both
the source line and the ground line when the main luminescent
device is able to light up; and electrically isolating at least one
of the first electrode and the second electrode from both the
source line and the ground line, electrically connecting the third
electrode to the source line, and electrically connecting the
fourth electrode to the ground line when the main luminescent
device is unable to light up.
8. The method of claim 7, wherein: fabricating the main luminescent
device comprises: disposing a first luminescent layer and the first
electrode on a first semiconductor layer of a first doping type;
disposing a second semiconductor layer of a second doping type on
the first luminescent layer; and disposing the second electrode on
the second semiconductor layer; and fabricating the redundant
luminescent device comprises: disposing a second luminescent layer
and the third electrode on a third semiconductor layer of the first
doping type; disposing a fourth semiconductor layer of the second
doping type on the second luminescent layer; and disposing the
fourth electrode on the fourth semiconductor layer.
9. A method of manufacturing and repairing micro lighting device,
comprising: fabricating a main luminescent device which includes a
first electrode and a second electrode; fabricating a redundant
luminescent device which includes a third electrode and a fourth
electrode; transferring the main luminescent device to be disposed
on a substrate; electrically connecting the first electrode to a
source line and electrically connecting the second electrode to a
ground line when the main luminescent device is able to light up;
electrically isolating at least one of the first electrode and the
second electrode from both the source line and the ground line when
the main luminescent device is able to light up; disposing the
redundant luminescent device on the main luminescent device; and
disposing a conductive material for electrically connecting the
third electrode to the source line and for electrically connecting
the fourth electrode to the ground line.
10. The method of claim 9, wherein: fabricating the main
luminescent device comprises: disposing a first luminescent layer
and the first electrode on a first semiconductor layer of a first
doping type; disposing a second semiconductor layer of a second
doping type on the first luminescent layer; and disposing the
second electrode on the second semiconductor layer; and fabricating
the redundant luminescent device comprises: disposing a second
luminescent layer and the third electrode on a third semiconductor
layer of the first doping type; disposing a fourth semiconductor
layer of the second doping type on the second luminescent layer;
and disposing the fourth electrode on the fourth semiconductor
layer.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority of Taiwan Application No.
106142619 filed on 2017 Dec. 5.
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0002] The present invention is related to a micro lighting device,
and more particularly, to a micro lighting device with repair
mechanism.
2. Description of the Prior Art
[0003] Compared to traditional incandescent bulbs, light-emitting
diodes (LEDs) are advantageous in low power consumption, long
lifetime, small size, no warm-up time, fast reaction speed, and the
ability to be manufactured as small or array devices. In addition
to outdoor displays, traffic signs, and liquid crystal display
(LCD) backlight for various electronic devices such as mobile
phones, notebook computers or personal digital assistants (PDAs),
LEDs are also widely used as indoor/outdoor lighting devices in
place of fluorescent of incandescent lamps.
[0004] The size of traditional LED arrays is the dimension of
millimeters (mm). The size of micro LED arrays may be reduced to
the dimension of micrometers (.mu.m) while inheriting the same good
performances regarding power consumption, brightness, resolution,
color saturation, reaction speed, life time and efficiency. In a
micro LED manufacturing process, a thin-film, miniaturized and
array design is adopted so that multiple micro LEDs are fabricated
in the dimension of merely 1-10 .mu.m. Next, these micro LEDs are
mass transferred to be disposed on another circuit board.
Protection layers and upper electrodes may be formed in a physical
deposition process before packaging the upper substrate. Since the
manufacturing process of micro LEDs is very complicated, there is a
need to improve manufacturing yield.
SUMMARY OF THE INVENTION
[0005] The present invention provides a micro lighting device
including a source line, a ground line, a main luminescent device
having a first electrode and a second electrode, and a redundant
luminescent device having a third electrode and a fourth electrode.
The first electrode is electrically connected to the source line
and the second electrode is electrically connected to the ground
line and at least one of the third electrode and the fourth
electrode is electrically isolated from both the source line and
the ground line when the main luminescent device is able to light
up. At least one of the first electrode and the second electrode is
electrically isolated from both the source line and the ground
line, the third electrode is electrically connected to the source
line and the fourth electrode is electrically connected to the
ground line when the main luminescent device is unable to light
up.
[0006] The present invention further provides a micro lighting
device including a source line, a ground line, a main luminescent
device having a first electrode and a second electrode, a redundant
luminescent device having a third electrode and a fourth electrode,
and a conductive material. The first electrode is electrically
connected to the source line and the second electrode is
electrically connected to the ground line when the main luminescent
device is able to light up. Both the first electrode and the second
electrode are electrically isolated from both the source line and
the ground line when the main luminescent device is unable to light
up. The redundant luminescent device is arranged to be disposed on
the main luminescent device when the main luminescent device is
unable to light up and the conductive material is used for
electrically connecting the third electrode to the source line and
for electrically connecting the fourth electrode to the ground
line.
[0007] The present invention further provides a method of
manufacturing and repairing micro lighting device. The method
includes fabricating a main luminescent device which includes a
first electrode and a second electrode and then transferring the
main luminescent device to be disposed on a substrate, fabricating
a redundant luminescent device which includes a third electrode and
a fourth electrode and then transferring the redundant luminescent
device to be disposed on the substrate, electrically connecting the
first electrode to a source line, electrically connecting the
second electrode to a ground line, and electrically isolating at
least one of the third electrode and the fourth electrode from both
the source line and the ground line when the main luminescent
device is able to light up, and electrically isolating at least one
of the first electrode and the second electrode from both the
source line and the ground line, electrically connecting the third
electrode to the source line, and electrically connecting the
fourth electrode to the ground line when the main luminescent
device is unable to light up.
[0008] The present invention further provides a method of
manufacturing and repairing micro lighting device. The method
includes fabricating a main luminescent device which includes a
first electrode and a second electrode, fabricating a redundant
luminescent device which includes a third electrode and a fourth
electrode, transferring the main luminescent device to be disposed
on a substrate, electrically connecting the first electrode to a
source line and electrically connecting the second electrode to a
ground line when the main luminescent device is able to light up,
electrically isolating at least one of the first electrode and the
second electrode from both the source line and the ground line when
the main luminescent device is able to light up, disposing the
redundant luminescent device on the main luminescent device, and
disposing a conductive material for electrically connecting the
third electrode to the source line and for electrically connecting
the fourth electrode to the ground line.
[0009] These and other objectives of the present invention will no
doubt become obvious to those of ordinary skill in the art after
reading the following detailed description of the preferred
embodiment that is illustrated in the various figures and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1A is a structural diagram illustrating a micro
lighting device according to an embodiment of the present
invention.
[0011] FIG. 1B is a diagram illustrating a method of repairing the
micro lighting device according to an embodiment of the present
invention.
[0012] FIG. 2A is a structural diagram illustrating a micro
lighting device according to another embodiment of the present
invention.
[0013] FIG. 2B is a diagram illustrating a method of repairing a
micro lighting device according to another embodiment of the
present invention.
[0014] FIG. 3A is a structural diagram illustrating a micro
lighting device according to another embodiment of the present
invention.
[0015] FIGS. 3B-3D are diagrams illustrating a method of repairing
a micro lighting device according to another embodiment of the
present invention.
DETAILED DESCRIPTION
[0016] FIG. 1A is a structural diagram illustrating a micro
lighting device 100 according to an embodiment of the present
invention. A cross-sectional diagram of the micro lighting device
100 is depicted on the left side of FIG. 1A, and a top-view diagram
of the micro lighting device 100 is depicted on the right side of
FIG. 1A. The micro lighting device 100 with a thin-film,
miniaturized and array design includes a plurality of main
luminescent devices (only one main luminescent device 10 is
depicted for illustrative purpose), at least one redundant
luminescent device 20, a source line 30, and a ground line 40.
[0017] The main luminescent device 10 and the redundant luminescent
device 20 are fabricated by combining P-type and N-type
semiconductor materials before being mass transferred to a
substrate 50. Under normal condition, when a positive voltage is
applied to a P-electrode and a negative voltage is applied to an
N-electrode, electrons flow from the N-region towards the P-region
and holes flow from the P-region towards the N-region due to the
forward-bias voltage. These electrons and holes then combine in the
PN junction of the luminescent layer, thereby emitting photons of
light. In an embodiment of the present invention, the main
luminescent device 10 and the redundant luminescent device 20 may
be micro LED devices. The main luminescent device 10 includes a
P-type semiconductor layer 12, an N-type semiconductor layer 14, a
P-electrode 16, an n-electrode 18, and a luminescent layer 15,
wherein the P-electrode 16 is electrically connected to the source
line 30 and the N-electrode 18 is electrically connected to the
ground line 40. The redundant luminescent device 20 includes a
P-type semiconductor layer 22, an N-type semiconductor layer 24, a
P-electrode 26, an n-electrode 28, and a luminescent layer 25,
wherein the P-electrode 26 is electrically connected to the source
line 30 but the N-electrode 18 is electrically isolated from the
ground line 40.
[0018] FIG. 1B is a diagram illustrating a method of repairing the
micro lighting device 100 according to an embodiment of the present
invention. A cross-sectional diagram of the repaired micro lighting
device 100 is depicted on the left side of FIG. 1B, and a top-view
diagram of the repaired micro lighting device 100 is depicted on
the right side of FIG. 1B, wherein the repair locations are
designated by flash signs. For illustrative purpose, it is assumed
that the main luminescent device 10 in FIG. 1A somehow malfunctions
and is unable to light up when applying voltages to the P-electrode
16 and the N-electrode 18, while the normal redundant luminescent
device 20 is unable to light up because no voltage can be applied
to the N-electrode 28. As depicted in FIG. 1B, the electrical
connection between the P-electrode 16 of the main luminescent
device 10 and the source line 30 may be cut off using laser cutting
technique so as to prevent leakage current from the flawed main
luminescent device 10. Next, the electrical connection between the
N-electrode 28 of the redundant luminescent device 20 and the
ground line 40 may be established using laser repair technique so
that the normal redundant luminescent device 20 may light up to
replace the flawed main luminescent device 10.
[0019] FIG. 2A is a structural diagram illustrating a micro
lighting device 200 according to another embodiment of the present
invention. A cross-sectional diagram of the micro lighting device
200 is depicted on the left side of FIG. 2A, and a top-view diagram
of the micro lighting device 200 is depicted on the right side of
FIG. 2A. The micro lighting device 200 with a thin-film,
miniaturized and array design includes a plurality of main
luminescent devices (only one main luminescent device 10 is
depicted for illustrative purpose), at least one redundant
luminescent device 20, a source line 30, and a ground line 40.
[0020] The main luminescent device 10 and the redundant luminescent
device 20 are fabricated by combining P-type and N-type
semiconductor materials before being mass transferred to a
substrate 50. Under normal condition, when a positive voltage is
applied to a P-electrode and a negative voltage is applied to an
N-electrode, electrons flow from the N-region towards the P-region
and holes flow from the P-region towards the N-region due to the
forward-bias voltage. These electrons and holes then combine in the
PN junction of the luminescent layer, thereby emitting photons of
light. In an embodiment of the present invention, the main
luminescent device 10 and the redundant luminescent device 20 may
be micro LED devices. The main luminescent device 10 includes a
P-type semiconductor layer 12, an N-type semiconductor layer 14, a
P-electrode 16, an n-electrode 18, and a luminescent layer 15,
wherein the P-electrode 16 is electrically connected to the source
line 30 and the N-electrode 18 is electrically connected to the
ground line 40. The redundant luminescent device 20 includes a
P-type semiconductor layer 22, an N-type semiconductor layer 24, a
P-electrode 26, an n-electrode 28, and a luminescent layer 25,
wherein the N-electrode 18 is electrically connected to the ground
line 40 but the P-electrode 26 is electrically isolated from the
source line 30.
[0021] FIG. 2B is a diagram illustrating a method of repairing the
micro lighting device 200 according to an embodiment of the present
invention. A cross-sectional diagram of the repaired micro lighting
device 200 is depicted on the left side of FIG. 2B, and a top-view
diagram of the repaired micro lighting device 200 is depicted on
the right side of FIG. 2B, wherein the repair locations are
designated by flash signs. For illustrative purpose, it is assumed
that the main luminescent device 10 in FIG. 2A somehow malfunctions
and is unable to light up when applying voltages to the P-electrode
16 and the N-electrode 18, while the normal redundant luminescent
device 20 is unable to light up because no voltage can be applied
to the P-electrode 26. As depicted in FIG. 2B, the electrical
connection between the N-electrode 18 of the main luminescent
device 10 and the ground line 40 may be cut off using laser cutting
technique so as to prevent leakage current from the flawed main
luminescent device 10. Next, the electrical connection between the
P-electrode 26 of the redundant luminescent device 20 and the
source line 30 may be established using laser repair technique so
that the normal redundant luminescent device 20 may light up to
replace the flawed main luminescent device 10.
[0022] FIG. 3A is a structural diagram illustrating a micro
lighting device 300 according to another embodiment of the present
invention. A cross-sectional diagram of the micro lighting device
300 is depicted on the left side of FIG. 3A, and a top-view diagram
of the micro lighting device 300 is depicted on the right side of
FIG. 3A. The micro lighting device 300 with a thin-film,
miniaturized and array design includes a plurality of main
luminescent devices (only two main luminescent devices 11 and 12
are depicted for illustrative purpose), a source line 30, and a
ground line 40.
[0023] The main luminescent devices 11 and 12 are fabricated by
combining P-type and N-type semiconductor materials before being
mass transferred to a substrate 50. Under normal condition, when a
positive voltage is applied to a P-electrode and a negative voltage
is applied to an N-electrode, electrons flow from the N-region
towards the P-region and holes flow from the P-region towards the
N-region due to the forward-bias voltage. These electrons and holes
then combine in the PN junction of the luminescent layer, thereby
emitting photons of light. In an embodiment of the present
invention, the main luminescent devices 11 and 12 may be micro LED
devices each including a P-type semiconductor layer 12, an N-type
semiconductor layer 14, a P-electrode 16, an n-electrode 18, and a
luminescent layer 15, wherein the P-electrode 16 is electrically
connected to the source line 30 and the N-electrode 18 is
electrically connected to the ground line 40.
[0024] FIGS. 3B-3D are diagrams illustrating a method of repairing
the micro lighting device 300 according to an embodiment of the
present invention. A cross-sectional diagram of the repaired micro
lighting device 300 is depicted on the left side of FIGS. 3B-3D,
and a top-view diagram of the repaired micro lighting device 300 is
depicted on the right side of FIGS. 3B-3D, wherein the repair
locations are designated by flash signs. For illustrative purpose,
it is assumed that the main luminescent device 11 in FIG. 3A
somehow malfunctions and is unable to light up when applying
voltages to its P-electrode 16 and its N-electrode 18, while the
normal main luminescent device 12 is able to light up when applying
voltages to its P-electrode 16 and its N-electrode 18. As depicted
in FIG. 3B, the electrical connection between the P-electrode 16 of
the main luminescent device 11 and the source line 30 and the
electrical connection between the N-electrode 18 of the main
luminescent device 11 and the ground line 40 may be cut off using
laser cutting technique so as to prevent leakage current from the
flawed main luminescent device 11. Next as depicted in FIG. 3C, a
redundant luminescent device 20 may be fabricated by combining
P-type and N-type semiconductor materials before being transferred
to be displaced on the main luminescent device 11. The redundant
luminescent device 20 includes a P-type semiconductor layer 22, an
N-type semiconductor layer 24, a P-electrode 26, an n-electrode 28,
and a luminescent layer 25. Next as depicted in FIG. 3D, conductive
material 35 may be deposited on the redundant luminescent device 20
so that the P-electrode 26 and the n-electrode 28 may be
electrically connected to the source line 30 and the ground line
40, respectively. Therefore, the normal redundant luminescent
device 20 may light up to replace the flawed main luminescent
device 11.
[0025] In an embodiment of the present invention, the conductive
material 35 may be tantalum, molybdenum or tungsten metal which may
be welded to the electrodes of the redundant luminescent device 20
in a laser metal transfer (LMT) process. In another embodiment of
the present invention, the conductive material 35 may be Ni(CO)4,
Fe(CO)5, Cr(CO)6, Mo(CO)6, or W(CO)6 metal compounds which may be
deposited on the electrodes of the redundant luminescent device 20
in a laser chemical vapor deposition (LCVD) process. However, the
type of the conductive material 35 does not limit the scope of the
present invention.
[0026] In conclusion, the present invention provides a micro
lighting device with repair mechanism. In addition to good
performances regarding power consumption, brightness, resolution,
color saturation, reaction speed, life time and efficiency, the
present micro lighting device can also improve manufacturing yield
using the repair mechanism.
[0027] Those skilled in the art will readily observe that numerous
modifications and alterations of the device and method may be made
while retaining the teachings of the invention. Accordingly, the
above disclosure should be construed as limited only by the metes
and bounds of the appended claims.
* * * * *