U.S. patent number RE48,474 [Application Number 16/168,198] was granted by the patent office on 2021-03-16 for light emitting device package and backlight unit comprising the same.
This patent grant is currently assigned to LUMENS CO., LTD.. The grantee listed for this patent is LUMENS CO., LTD.. Invention is credited to Bo Hyun Chung, Cheol Hun Jung, Pyoung Gug Kim, Seung Hoon Lee, Jun Hyung Lim, Jung A Lim, Chun Ki Min, Seung Hyun Oh.
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United States Patent |
RE48,474 |
Oh , et al. |
March 16, 2021 |
Light emitting device package and backlight unit comprising the
same
Abstract
Disclosed is a light emitting element package having excellent
heat radiation performance and high luminance, and a backlight unit
including the same. The light emitting element package includes a
package including a lead frame, a light emitting element provided
on the lead frame, and a molded material combined with the lead
frame and having an opening for emitting light generated by the
light emitting element, and a reflection structure having an
opening corresponding to the opening of the molded material, and
contacting the molded material.
Inventors: |
Oh; Seung Hyun (Gwangju-si,
KR), Kim; Pyoung Gug (Hwaseong-si, KR),
Lee; Seung Hoon (Yongin-si, KR), Min; Chun Ki
(Yongin-si, KR), Lim; Jung A (Seoul, KR),
Lim; Jun Hyung (Seoul, KR), Jung; Cheol Hun
(Osan-si, KR), Chung; Bo Hyun (Seoul, KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
LUMENS CO., LTD. |
Yongin-si |
N/A |
KR |
|
|
Assignee: |
LUMENS CO., LTD. (Yongin-si,
KR)
|
Family
ID: |
1000005148715 |
Appl.
No.: |
16/168,198 |
Filed: |
October 23, 2018 |
PCT
Filed: |
November 16, 2012 |
PCT No.: |
PCT/KR2012/009752 |
371(c)(1),(2),(4) Date: |
May 16, 2014 |
PCT
Pub. No.: |
WO2013/073897 |
PCT
Pub. Date: |
May 23, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
15147351 |
May 5, 2016 |
RE47444 |
|
|
Reissue of: |
14358994 |
Nov 16, 2012 |
9142747 |
Sep 22, 2015 |
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Reissue of: |
14358994 |
Nov 16, 2012 |
9142747 |
Sep 22, 2015 |
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Foreign Application Priority Data
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Nov 17, 2011 [KR] |
|
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10-2011-0120496 |
Sep 4, 2012 [KR] |
|
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10-2012-0097844 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L
33/486 (20130101); H01L 33/62 (20130101); H01L
33/60 (20130101); H01L 33/54 (20130101); H01L
33/60 (20130101); H01L 33/62 (20130101); H01L
33/54 (20130101); H01L 33/486 (20130101); G02F
1/133614 (20210101); H01L 2224/48247 (20130101); G02F
1/133614 (20210101); G02B 6/0031 (20130101); H01L
2924/181 (20130101); G02F 1/133615 (20130101); H01L
2924/181 (20130101); H01L 2224/48091 (20130101); G02B
6/0085 (20130101); G02B 6/0073 (20130101); G02B
6/0085 (20130101); H01L 2224/48091 (20130101); G02B
6/0073 (20130101); G02F 1/133615 (20130101); G02B
6/0031 (20130101); H01L 2224/48247 (20130101); H01L
2224/48091 (20130101); H01L 2224/48091 (20130101); H01L
2924/00014 (20130101); H01L 2924/00014 (20130101); H01L
2924/181 (20130101); H01L 2924/181 (20130101); H01L
2924/00012 (20130101); H01L 2924/00012 (20130101) |
Current International
Class: |
H01L
33/48 (20100101); H01L 33/60 (20100101); H01L
33/62 (20100101); H01L 33/54 (20100101); G02F
1/13357 (20060101); F21V 8/00 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
1497742 |
|
May 2004 |
|
CN |
|
1770488 |
|
May 2006 |
|
CN |
|
1900792 |
|
Jan 2007 |
|
CN |
|
101147270 |
|
Mar 2008 |
|
CN |
|
2006128511 |
|
May 2006 |
|
JP |
|
10-0730076 |
|
Jun 2007 |
|
KR |
|
20070056233 |
|
Jun 2007 |
|
KR |
|
1020070056230 |
|
Jun 2007 |
|
KR |
|
10-0769718 |
|
Oct 2007 |
|
KR |
|
Other References
English Translation of JP-2006-128511 (Year: 2006). cited by
examiner .
English Translation of KR-100769718 (Year: 2007). cited by examiner
.
Communication from European Patent Office dated Nov. 6, 2018 in EP
Application No. 18174472.3, enclosing extended European search
report. cited by applicant .
International Search Report mailed Apr. 16, 2013;
PCT/KR2012/009752. cited by applicant.
|
Primary Examiner: Xu; Ling X
Attorney, Agent or Firm: Mei & Mark LLP
Claims
The invention claimed is:
.[.1. A light emitting element package, comprising: a lead frame; a
light emitting element on the lead frame; a molded material
combined with the lead frame and having an opening for emitting
light generated by the light emitting element; a reflection
structure having an opening that corresponds to the opening of the
molded material and contacting the molded material; and an adhesive
layer provided in at least part of a region between the molded
material and the reflection structure to fix the reflection
structure onto the molded material, wherein the adhesive layer has
a first thickness in an area adjacent to the light emitting element
and a second thickness in an area away from the light emitting
element, and wherein the first thickness is greater than the second
thickness..].
.[.2. The light emitting element package according to claim 1,
wherein the reflection structure comprises: a supporting portion
contacting the molded material and provided continuously or
discretely along a circumference of the opening of the molded
material; and a radial portion contacting the supporting portion
and extending radially from the molded material relative to a
direction along which light generated by the light emitting element
emits..].
.[.3. The light emitting element package according to claim 1,
wherein the molded material comprises a supporting portion provided
continuously or discretely along a circumference of the opening of
the molded material, and wherein the reflection structure comprises
a radial portion contacting the supporting portion and having a
radial shape extending radially from the molded material relative
to a direction along which light generated by the light emitting
element emits..].
.[.4. The light emitting element package according to claim 1,
wherein the molded material comprises a supporting portion provided
continuously or discretely along a circumference of the opening of
the molded material, and wherein the reflection structure has a
shape that corresponds to the supporting portion of the molded
material, and contacts the molded material..].
.[.5. The light emitting element package according to claim 1,
wherein recesses or concave and convex portions are provided on the
molded material, and wherein the reflection structure is fitted
into the recesses or concave and convex portions..].
.[.6. The light emitting element package according to claim 1,
wherein the thickness of the adhesive layer is gradually reduced
away from the light emitting element..].
.[.7. A light emitting element package, comprising: a lead frame; a
light emitting element on the lead frame; a molded material
combined with the lead frame and haying an opening for emitting
light generated by the light emitting element; and a reflection
structure having an opening that corresponds to the opening of the
molded material and contacting the molded material, wherein the
reflection structure comprises a radial surface formed in a radial
shape extending radially from the molded material relative to a
direction along which light generated by the light emitting element
emits, and wherein the radial surface of the reflection structure
forms a first angle with a main emission direction of light
generated by the light emitting element, from a point where the
radial surface contacts the molded material to a first point away
from the molded material, and forms a second angle with the main
emission direction from the first point to a second point further
away from the molded material compared to the first point, wherein
the second angle is greater than the first angle..].
.[.8. The light emitting element package according to claim 7,
further comprising a first resin layer that includes a fluorescent
material and is provided in the opening of the molded material to
cover the light emitting element..].
.[.9. The light emitting element package according to claim 8,
further comprising a light-transmitting second resin layer that
covers the first resin layer and contacts the radial
surface..].
.[.10. The light emitting element package according to claim 7,
further comprising: a light-transmitting second resin layer
provided in the opening of the molded material to cover the light
emitting element; and a first resin layer that includes a
fluorescent material, covers the second resin layer, and contacts
the radial surface..].
.[.11. The light emitting element package according to claim 1,
wherein the reflection structure comprises metal..].
.[.12. The light emitting element package according to claim 1,
wherein a surface of the supporting portion facing the opening of
the molded material has a radial shape extending radially relative
to a direction along which light generated by the light emitting
element emits..].
.[.13. The light emitting element package according to claim 1,
wherein part of the reflection structure is inserted into the
opening of the molded material, and Wherein the other part of the
reflection structure, protruding from the opening of the molded
material has a radial shape extending radially from the molded
material relative to a direction along which light generated by the
light emitting element emits..].
.[.14. A light emitting element package, comprising: a lead frame;
a light emitting element on the lead frame; a molded material
combined with the lead frame and having an opening for emitting
light generated by the light emitting element; a reflection
structure having an opening that corresponds to the opening of the
molded material, and contacting the molded material; a supporting
portion provided discretely or continuously on the molded material
to fix the reflection structure onto the molded material; and an
adhesive layer provided in at least part of a region between the
molded material and the reflection structure, and having a first
thickness in an area adjacent to the light emitting element and a
second thickness in an area away from the light emitting element,
wherein the first thickness is greater than the second
thickness..].
.[.15. A backlight unit, comprising: a reflective sheet; a light
guide plate on or above the reflective sheet; and alight emitting
element package according to claim 1, configured to illuminate the
light guide plate..].
.Iadd.16. A method of manufacturing a light emitting element
package, comprising: providing a lead frame, a light emitting
element, and a molded material in a package, the molded material
having an opening for emitting light generated by the light
emitting element; aligning a reflection structure in contact with
the molded material, the reflection structure having an opening
that corresponds to the opening of the molded material; and fixing
the reflection structure onto the molded material with an adhesive
layer provided between the molded material and the reflection
structure, the adhesion layer having a first thickness in an area
adjacent to the light emitting element and a second thickness less
than the first thickness in an area away from the light emitting
element. .Iaddend.
.Iadd.17. The method of claim 16, further comprising providing a
supporting portion that contacts the molded material continuously
or discretely along a circumference of the opening of the molded
material. .Iaddend.
.Iadd.18. The method of claim 17, wherein the support portion
extends along the circumference of the opening of the molded
material and protrude from corners of the molded material along a
z-axis generally parallel to a direction of light emitted by the
light emitting element. .Iaddend.
.Iadd.19. The method of claim 16, wherein recesses or concave and
convex portions are provided on the molded material, and at least a
portion of the reflection structure is fitted into the recesses or
concave and convex portions. .Iaddend.
.Iadd.20. The method of claim 16, wherein the reflection structure
comprises a radial surface formed in a radial shape extending
radially from the molded material relative to a direction along
which light generated by the light emitting element emits.
.Iaddend.
.Iadd.21. The method of claim 20, wherein the radial surface of the
reflection structure forms a first angle with a main emission
direction of light generated by the light emitting element from a
point where the radial surface contacts the molded material to a
first point away from the molded material and forms a second angle
with the main emission direction from the first point to a second
point further away from the molded material compared to the first
point, wherein the second angle is greater than the first angle.
.Iaddend.
.Iadd.22. The method of claim 16, further comprising filling a
first resin layer comprising a fluorescent material in the opening
of the molded material to cover the light emitting element.
.Iaddend.
.Iadd.23. The method of claim 22, further comprising covering the
first resin layer with a second resin layer, wherein the second
resin layer contacts a radial surface of the reflective structure.
.Iaddend.
.Iadd.24. The method of claim 16, further comprising filling a
light-transmitting second resin layer in the opening of the molded
material to cover the light emitting element and covering the
second resin layer with a first resin layer comprising a
fluorescent material, wherein the first resin layer contacts a
radial surface of the reflective structure. .Iaddend.
.Iadd.25. A method of manufacturing a light emitting element
package, comprising: providing a lead frame, a light emitting
element, and a molded material in a package, the molded material
having a first opening for emitting light generated by the light
emitting element, the first opening being defined by a first inner
surface having a first slope line; aligning a reflection structure
in contact with the molded material, the reflection structure
having a second opening that corresponds to the first opening of
the molded material, the second opening being defined by a second
inner surface having a second slope line; and fixing the reflection
structure onto the molded material, such that the first slope line
and the second slope line form a continuous straight line, wherein
fixing the reflection structure onto the molded material comprises
providing an adhesive layer between the molded material and the
reflection structure, wherein the adhesive layer has a first
thickness in an area adjacent to the light emitting element and a
second thickness in an area away from the light emitting element,
and wherein the first thickness is greater than the second
thickness. .Iaddend.
.Iadd.26. The method of claim 25, wherein the first inner surface
and the second inner surface define a common circumference when the
reflection structure is fixed onto the molded material.
.Iaddend.
.Iadd.27. The method of claim 25, wherein the lead frame is exposed
to an exterior of the molded material. .Iaddend.
.Iadd.28. The method of claim 27, wherein the second inner surface
is in flush with the first inner surface along all circumferential
direction of the first opening of the molded material.
.Iaddend.
.Iadd.29. The method of claim 25, wherein the adhesive layer is not
exposed either to the first opening and the second opening.
.Iaddend.
.Iadd.30. The method of claim 25, further comprising providing
recesses or concave and convex portions on the molded material and
fitting a portion of the reflection structure into the recesses or
concave and convex portions. .Iaddend.
.Iadd.31. A method of manufacturing a light emitting element
package, comprising: providing a lead frame, a light emitting
element, and a molded material in a package, the molded material
having a first inner surface defining a first opening for emitting
light generated by the light emitting element; aligning a
reflection structure in contact with the molded material, the
reflection structure having a second inner surface defining a
second opening that corresponds to the first opening of the molded
material; and fixing the reflection structure onto the molded
material, wherein the molded material comprises a plurality of
recesses along a circumference of the first opening of the molded
material, and the reflection structure comprises a plurality of
protrusions along a circumference of the second opening of the
reflection structure, and wherein fixing the reflection structure
onto the molded material comprises mating the plurality of
protrusions of the reflection structure with the plurality of
recesses of the molded material and providing an adhesive layer
between the molded material and the reflection structure, wherein
the adhesive layer has a first thickness in an area adjacent to the
light emitting element and a second thickness in an area away from
the light emitting element, and wherein the first thickness is
greater than the second thickness. .Iaddend.
.Iadd.32. The method of claim 31, wherein the molded material has a
substantially rectangular outer shape. .Iaddend.
.Iadd.33. The method of claim 32, wherein at least two opposing
sides of the molded material comprises each of the plurality of
recesses. .Iaddend.
Description
.Iadd.Notice: More than one reissue application has been filed for
the reissue of U.S. Pat. No. 9,142,747. Currently, U.S. application
Ser. No. 15/147,351, filed May 5, 2016, is another application for
reissue of U.S. Pat. No. 9,142,747. .Iaddend.
.Iadd.This application is a continuation reissue of U.S.
application Ser. No. 15/147,351, filed May 5, 2016, which is an
application for reissue of U.S. Pat. No. 9,142,747. .Iaddend.
TECHNICAL FIELD
The present invention relates to a light emitting element package
and a backlight unit including the same. More particularly, the
present invention relates to a light emitting element package
having excellent heat radiation performance and high luminance, and
a backlight unit including the same.
BACKGROUND ART
In general, a light emitting element is used as a light source of a
backlight unit in an electronic device, e.g., display device. A
light emitting element may be packaged in various ways before being
connected to a backlight module and a backlight unit includes a
packaged light emitting element.
The light emitting element of the light emitting element package
generates not only light but also a considerable amount of
heat.
DETAILED DESCRIPTION OF THE INVENTION
Technical Problem
However, in the above-described conventional light emitting element
package, heat generated by the light emitting element may not be
easily discharged to the outside. As a result, a molded material
may inflate or the life span of the light emitting element may be
shortened.
The present invention has been made in an effort to solve various
problems including the above problem, and provides a light emitting
element package having excellent heat radiation performance and
high luminance, and a backlight unit including the same. However,
the scope of the present invention is not limited thereto.
Technical Solution
According to an aspect of the present invention, there is provided
a light emitting element package including a lead frame, a light
emitting element on the lead frame, a molded material combined with
the lead frame and having an opening for emitting light generated
by the light emitting element, and a reflection structure having an
opening that corresponds to the opening of the molded material, and
contacting the molded material.
The reflection structure may include a supporting portion
contacting the molded material and provided continuously or
discretely along a circumference of the opening of the molded
material, and a radial portion contacting the supporting portion
and extending radially from the molded material relative to a
direction along which light generated by the light emitting element
emits.
The molded material may include a supporting portion provided
continuously or discretely along a circumference of the opening of
the molded material, and the reflection structure may include a
radial portion contacting the supporting portion and having a
radial shape extending radially from the molded material relative
to a direction along which light generated by the light emitting
element emits.
The molded material may include a supporting portion provided
continuously or discretely along a circumference of the opening of
the molded material, and the reflection structure may have a shape
that corresponds to the supporting portion of the molded material
and contact the molded material.
Recesses or concave and convex portions may be provided on the
molded material, and the reflection structure may be fitted into
the recesses or concave and convex portions.
The light emitting element package may further include an adhesive
layer provided in at least part of a region between the molded
material and the reflection structure to fix the reflection
structure onto the molded material.
The adhesive layer may have a first thickness in an area adjacent
to the light emitting element and a second thickness in an area
away from the light emitting element, and the first thickness may
be greater than the second thickness.
The thickness of the adhesive layer may be gradually reduced away
from the light emitting element.
The reflection structure may include a radial surface formed in a
radial shape extending radially from the molded material relative
to a direction along which light generated by the light emitting
element emits.
The radial surface of the reflection structure may form a
predetermined angle with a main emission direction of light
generated by the light emitting element emits.
The predetermined angle may be equal to or greater than 10.degree.
and equal to or less than 20.degree..
The radial surface of the reflection structure may form a first
angle with to a main emission direction of light generated by the
light emitting element, from a point where the radial surface
contacts the molded material to a first point away from the molded
material, and form a second angle with the main emission direction
from the first point to a second point further away from the molded
material compared to the first point, and the second angle may be
greater than the first angle.
The light emitting element package may further include a first
resin layer that includes a fluorescent material and be provided in
the opening of the molded material to cover the light emitting
element.
The light emitting element package may further include a
light-transmitting second resin layer that covers the first resin
layer and contacts the radial surface.
The light emitting element package may further include a
light-transmitting second resin layer provided in the opening of
the molded material to cover the light emitting element, and a
first resin layer that includes a fluorescent material, covers the
second resin layer, and contacts the radial surface.
The reflection structure may comprise metal.
A surface of the supporting portion facing the opening of the
molded material may have a radial shape extending radially relative
to a direction along which light generated by the light emitting
element emits.
Part of the reflection structure may be inserted into the opening
of the molded material, and the other part of the reflection
structure, protruding from the opening of the molded material may
have a radial shape extending radially from the molded material
relative to a direction along which light generated by the light
emitting element emits.
According to another aspect of the present invention, there is
provided a light emitting element package including a lead frame, a
light emitting element on the lead frame, a molded material
combined with the lead frame and having an opening for emitting
light generated by the light emitting element, a reflection
structure having an opening that corresponds to the opening of the
molded material, and contacting the molded material, a supporting
portion provided discretely or continuously on the molded material
to fix the reflection structure onto the molded material, and an
adhesive layer provided in at least part of a region between the
molded material and the reflection structure, and having a first
thickness in an area adjacent to the light emitting element and a
second thickness in an area away from the light emitting element,
wherein the first thickness is greater than the second
thickness.
According to yet another aspect of the present invention, there is
provided a backlight unit including a reflective sheet, a light
guide plate on or above the reflective sheet, and a light emitting
element package configured to illuminate the light guide plate.
Advantageous Effects
According to an embodiment of the present invention, a light
emitting element package having excellent heat radiation
performance and high luminance, and a backlight unit including the
same may be provided. However, the scope of the present invention
is not limited thereto.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross-sectional view of a light emitting
element package according to an embodiment of the present
invention;
FIG. 2 is a partial schematic perspective view of the light
emitting element package of FIG. 1;
FIGS. 3 and 4 are schematic cross-sectional views showing a
manufacturing method of a light emitting element package, according
to another embodiment of the present invention;
FIGS. 5 and 6 are schematic cross-sectional views showing a
manufacturing method of a light emitting element package, according
to yet another embodiment of the present invention;
FIGS. 7 and 8 are schematic cross-sectional views showing a
manufacturing method of a light emitting element package, according
to yet another embodiment of the present invention;
FIG. 9 is a partial schematic perspective view of a light emitting
element package according to yet another embodiment of the present
invention;
FIG. 10 is a schematic perspective view of a light emitting element
package according to yet another embodiment of the present
invention;
FIG. 11 is an exploded perspective view of the light emitting
element package of FIG. 10;
FIG. 12 is a schematic cross-sectional view taken along line
XII-XII of FIG. 10;
FIG. 13 is a schematic cross-sectional view of a light emitting
element package according to yet another embodiment of the present
invention;
FIG. 14 is a schematic cross-sectional view showing paths of as
well as surfaces illuminated by light emitted from the light
emitting element package according to embodiments of the present
invention;
FIG. 15 is a schematic graph showing a beam angle of light emitted
from the light emitting element package according to embodiments of
the present invention;
FIG. 16 is a partial schematic perspective view of a light emitting
element according to yet another embodiment of the present
invention; and
FIG. 17 is a schematic side elevation view of a backlight unit
according to an embodiment of the present invention.
BEST MODE
Hereinafter, embodiments of the present invention will be described
in detail with reference to the attached drawings. The present
invention may, however, be embodied in many different forms and
should not be construed as being 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
concept of the invention to a person having ordinary skill in the
art. In the drawings, the sizes of elements may be exaggerated or
reduced for convenience of explanation.
In the following description, x, y, and z axes are not limited to
three axes on a Cartesian coordinate system, and may be construed
in a broad sense to include those axes. For example, the x, y, and
z axes may be perpendicular to each other but may also refer to
different non-perpendicular directions.
FIG. 1 is a schematic cross-sectional view of a light emitting
element package according to an embodiment of the present
invention, and FIG. 2 is a partial schematic perspective view of
the light emitting element package of FIG. 1. The cross-sectional
view of FIG. 1 may be understood to be one taken along line I-I of
FIG. 2. The light emitting element package according to this
embodiment includes a package and a reflection structure 40 as
illustrated in FIGS. 1 and 2. The package includes a lead frame 10,
a light emitting element 20, and a molded material 30, and the
reflection structure 40 includes a supporting portion 41 and a
radial portion 42.
The lead frame 10 includes a first lead 11 and a second lead 12.
The lead frame 10 may further include another lead(s). For example,
the lead frame 10 may include a die pad for mounting the light
emitting element 20 to be described below, and first and second
leads spaced apart from the die pad.
The light emitting element 20 is provided on the lead frame 10, for
example, on the first lead 11 as illustrated in FIGS. 1 and 2. The
light emitting element 20 is an element for emitting light by
receiving an electrical signal and may be used as a light source
for various electronic devices. For example, the light emitting
element include a diode of a compound semiconductor, and may be
referred to as a light emitting diode (LED). The LED may emit light
of various colors depending on materials of the compound
semiconductor.
The light emitting element 20 may be electrically connected to the
first lead 11 and/or the second lead 12, either by an electrically
conductive adhesive member or to through wiring. Referring to FIG.
1, the light emitting element 20 is illustrated to be electrically
connected to each of the first and second leads 11 and 12 through
wiring. Wiring is not illustrated in FIG. 2.
The molded material 30 may be connected to the lead frame 10 to
form an external shape of the whole light emitting element package.
The molded material 30 has an opening 30a through which light
generated by the light emitting element 20 passes. In FIGS. 1 and
2, the molded material 30 is illustrated to have the opening 30a
capable of allowing light generated by the light emitting element
20 to proceed in the positive z direction. .Iadd.The inner surface
of the molded material 30 facing with the opening 30a thereof has a
first slope line S1. The inner surface of the molded material may
have the first slope line S1 in all circumferential direction of
the opening 30a of the molded material 30.Iaddend..
The molded material 30 may be formed of a resin by, for example,
transfer molding. Various modifications are possible and thus the
molded material 30 may be formed by injection molding other than
transfer molding. The resin for the molded material 30 may include,
for example, epoxy.
A first resin layer 51 may be provided within the opening 30a of
the molded material 30 such that the light emitting element 20 is
covered and protected against, for example, external moisture. A
fluorescent material may be mixed into the first resin layer 51 and
the opening 30a of the molded material 30 may be completely or
partially filled with the first resin layer 51. The opening may be
partially filled with the first resin layer 51 mixed with the
fluorescent material, and a (transparent) filler having no
fluorescent material may be additionally provided to fill the
remaining area. When the opening 30a of the molded material 30 is
filled with the first resin layer 51, the opening will be filled as
high as the top edge of the opening 30a of the molded material 30,
that is, the bottom edge of the supporting portion 41 of the
reflection structure 40, which will be described below. The first
resin layer 51 is not illustrated in FIG. 2.
The reflection structure 40 has an opening .Iadd.40a .Iaddend.that
corresponds to the opening 30a of the molded material 30, and
contacts the molded material 30. .Iadd.The inner surface of the
reflection structure 40 facing with the opening 40a thereof has a
second slope line S.sub.2. The inner surface of the reflection
structure 40 may have the second slope line S.sub.2 in all
circumferential direction of the opening 40a of the reflection
structure 40. The second slope line S.sub.2 and the first slope
line S.sub.1 may form a straight line. Furthermore, the inner
surface of the reflection structure 40 facing with the opening 40a
thereof may flush with the inner surface of the molded material 30
facing with the opening 30a thereof along all circumferential
direction of the opening 30a of the molded material 30.
.Iaddend.The reflection structure 40 may be formed of a metallic
material having excellent thermal conductivity. Particularly, the
reflection structure 40 may include the supporting portion 41 and
the radial portion 42.
The supporting portion 41 contacts the molded material 30 and may
be continuously provided along the circumference of the opening 30a
of the molded material 30. The supporting portion 41 is illustrated
to continuously surround the opening 30a of the molded material 30
in FIGS. 1 and 2.
The radial portion 42 is provided to contact the supporting portion
41. The radial portion 42 is illustrated to contact the supporting
portion 41 and also contact a top surface of the molded material 30
in a light emitting direction (the positive z direction) in FIGS. 1
and 2, but the present invention is not limited thereto. That is,
the radial portion 42 may not contact the molded material 30 but
contact the supporting portion 41 only. The radial portion 42 and
the supporting portion 41 may be provided as one body.
The radial portion 42 has a radial shape. Particularly, the radial
portion 42 may be formed in a radial shape extending radially from
the molded material relative to a direction along which light
generated by the light emitting element emits (the positive z
direction). The radial shape of the radial portion 42 may be formed
with respect to an axis that passes through the centers of the
light emitting element 20 and the opening 30a of the molded
material 30 (z axis).
A second resin layer 52 may be further provided. Here, the second
resin layer 52 covers the first resin layer 51 and contacts the
radial portion 42. The second resin layer 52 contacting the radial
portion 42 may be understood to be the second resin layer 52
contacting an internal radial surface of the radial portion 42.
The second resin layer 52 may be formed of a light-transmitting
material, e.g., an epoxy or silicone resin. The second resin layer
52 contacts the first resin layer 51 and the radial portion 42
(radiation surface) and thus may prevent the reflection structure
40 from being separated from, for example, the molded material 30.
The second resin layer 52 may fill the reflection structure 40 as
high as the top edge of the supporting portion 41 as illustrated in
FIG. 1. The second resin layer 52 is not illustrated in FIG. 2.
Although the first resin layer 51, into which a fluorescent
material is mixed, is provided in the opening 30a of the molded
material 30 to cover the light emitting element 20, and the second
resin layer 52 is provided to cover the first resin layer 51 and
contact the radial portion 42 (radiation surface) in the above
description, the relative positions of the first and second resin
layers 51 and 52 may be switched. For example, a light-transmitting
second resin layer may be provided in the opening 30a of the molded
material 30 to cover the light emitting element 20, and a first
resin layer, into which a fluorescent material is mixed, may be
provided to cover the second resin layer and contact the radial
portion 42 (radiation surface).
Here, since the second resin layer is provided between the light
emitting element 20 and the first resin layer into which the
fluorescent material is mixed, the distance between the light
emitting element 20 and the first resin layer into which the
fluorescent material is mixed may be controlled using the second
resin layer. If the distance between the light emitting element 20
and the first resin layer into which the fluorescent material is
mixed decreases, the color temperature of light ultimately emitted
to the outside is lowered. Consequently, the color temperature of
light ultimately emitted to the outside may be controlled by
adjusting the thickness of the second resin layer.
As described above, the light emitting element 20 generates not
only light but also a considerable amount of heat. In a
conventional light emitting element package, heat generated by a
light emitting element may not be easily discharged to the outside.
As a result, a molded material may inflate or the life span of the
light emitting element shortened.
The light emitting element package according to the .[.this.].
embodiment includes the reflection structure 40, provided near the
light emitting element 20 and contacting the molded material 30,
and thus heat generated by the light emitting element 20 may be
effectively discharged to the outside through the reflection
structure 40. In particular, the radial portion 42 of the
reflection structure 40 has a radial-shaped structure that is open
to the outside of the molded material 30, and thus the heat
generated by the light emitting element 20 and absorbed by the
reflection structure 40 may be effectively discharged to the
outside.
Some of the light generated by the light emitting element 20
proceeds along a direction between the positive z direction and the
positive x direction, as well as along the positive z direction.
The luminance in a forward direction of the light emitting element
package may be greatly increased by having the above described
light reflected on the internal surface 42' of the radial portion
42 of the reflection structure and then proceed approximately along
the positive z direction. That is, the internal surface 42' of the
radial portion 42 of the reflection structure 40 may function as a
reflective surface together with a tilted side surface 30' of the
opening 30a of the molded material 30.
A reflective portion may be formed only of the internal side
surface 30' of the opening 30a of the molded material 30, but there
may exist light that proceeds along a direction between the
positive z direction and the positive x direction without reaching
the internal side surface 30' of the opening 30a of the molded
material 30. In the light emitting element package according to the
current embodiment, the above described light may also be reflected
on the internal surface 42' of the radial portion 42 provided
outside the molded material 30 and then proceed approximately along
the positive z direction.
The internal surface 42' of the radial portion 42 of the reflection
structure 40 may be coated with a reflective material such as
silver to improve reflectivity. For convenience, parts other than
the internal surface 42' may also be coated.
Mode of the Invention
FIGS. 3 and 4 are schematic cross-sectional views showing a
manufacturing method of a light emitting element package, according
to another embodiment of the present invention. Referring to FIG.
3, the package that includes the lead frame 10, the light emitting
element 20, and the molded material 30, and the reflection
structure 40 that includes the supporting portion 41 and the radial
portion 42 are prepared. The package includes the first resin layer
51 that fills the opening 30a of the molded material 30 to cover
the light emitting element 20.
After that, the package and the reflection structure 40 are aligned
to contact each other as illustrated in FIG. 4, and then the second
resin layer 52 is formed on the first resin layer 51, thereby
manufacturing the light emitting element package illustrated in
FIG. 1. The second resin layer 52 may prevent the reflection
structure 40 from being separated from the molded material 30.
One package and one reflection structure 40 are aligned and
combined in FIGS. 3 and 4, but the present invention is not limited
thereto. For example, a plurality of lead frames 10 of packages may
be aligned and connected to each other, a plurality of reflection
structures 40 may be aligned and connected to each other, and then
the packages and the reflection structures 40 may be combined and
cut, thereby simultaneously manufacturing a plurality of light
emitting element packages each of which having a reflection
structure. This also applies to the following embodiments and
modifications thereof.
Meanwhile, as described above, the package that includes the first
resin layer 51 filling the opening 30a of the molded material 30 to
cover the light emitting element 20 is prepared as illustrated in
FIG. 3, the package and the reflection structure 40 are aligned to
contact each other as illustrated in FIG. 4, and then the second
resin layer 52 is formed on the first resin layer 51, thereby
manufacturing the light emitting element package illustrated in
FIG. 1. However, the present invention is not limited thereto. For
example, a package that includes a light-transmitting second resin
layer filling the opening 30a of the molded material 30 to cover
the light emitting element 20 may be prepared, the package and the
reflection structure 40 may be aligned to contact each other, and
then a first resin layer into which a fluorescent material is mixed
may be formed on the second resin layer, thereby manufacturing a
light emitting element package.
Here, since the second resin layer is provided between the light
emitting element 20 and the first resin layer into which the
fluorescent material is mixed, the distance between the light
emitting element 20 and the first resin layer into which the
fluorescent material is mixed may be controlled using the second
resin layer. If the distance between the light emitting element 20
and the first resin layer into which the fluorescent material is
mixed decreases, the color temperature of light ultimately emitted
to the outside is lowered. Consequently, the color temperature of
light ultimately emitted to the outside may be controlled by
adjusting the thickness of the second resin layer.
FIGS. 5 and 6 are schematic cross-sectional views showing a
manufacturing method of a light emitting element package, according
to yet another embodiment of the present invention. Referring to
FIG. 5, the package that includes the lead frame 10, the light
emitting element 20, and the molded material 30, and the reflection
structure 40 that includes the supporting portion 41 and the radial
portion 42 are prepared. The package does not include the first
resin layer 51.
After that, the package and the reflection structure 40 are aligned
to contact each other as illustrated in FIG. 6, the first resin
layer 51 that fills the opening 30a of the molded material 30 to
cover the light emitting element 20 is formed, and then the second
resin layer 52 is formed on the first resin layer 51, thereby
manufacturing the light emitting element package illustrated in
FIG. 1. The second resin layer 52 may prevent the reflection
structure 40 from being separated from the molded material 30.
However, unlike this, after the package and the reflection
structure 40 are aligned to contact each other as illustrated in
FIG. 6, the first resin layer 51, into which a fluorescent material
is mixed, may not only fill the opening 30a of the molded material
30 to cover the light emitting element 20 but also contact the
reflection structure 40, without a second resin layer being formed.
Here, the first resin layer 51 may contact part of the radial
portion 42, or may completely fill the opening of the radial
portion 42 lest the internal surface 42' of the radial portion 42
is exposed.
Alternatively, after the package and the reflection structure 40
are aligned to contact each other as illustrated in FIG. 6, a
second resin layer may fill the opening 30a of the molded material
30 to cover the light emitting element 20, and then a first resin
layer into which a fluorescent material is mixed may be formed on
the second resin layer. Here, the second resin layer may not
contact the reflection structure 40 and the first resin layer may
contact the reflection structure 40, or the second resin layer may
contact the reflection structure 40 and the first resin layer
thereon may also contact the reflection structure 40.
Heretofore, the reflection structure has been illustrated to
include a supporting portion and a radial portion, but the present
invention is not limited thereto. That is, the supporting portion
may be part of a molded material and the reflection structure may
include the radial portion only. For example, the supporting
portion continuously or discretely disposed along the circumference
of an opening of the molded material may be one of the components
of the molded material. Furthermore, the reflection structure may
include the radial portion contacting the supporting portion of the
molded material and formed in a radial shape extending radially
from the molded material relative to a direction along which light
generated by the light emitting element emits.
FIGS. 7 and 8 are schematic cross-sectional views showing a
manufacturing method of a light emitting element package, according
to yet another embodiment of the present invention. In this
embodiment, a structure wherein the package and the reflection
structure 40 are combined is firstly prepared as illustrated in
FIG. 7.
Here, the reflection structure 40 has a shape different from that
of the reflection structure according to the preceding embodiments.
In the manufacturing process according to this embodiment, part of
the reflection structure 40 may be inserted into the opening 30a of
the molded material 30, and the other part of the reflection
structure 40, protruding from the opening 30a of the molded
material 30, may be formed in a radial shape extending radially
from the molded material relative to a direction along which light
generated by the light emitting element 20 emits. That is, unlike
the preceding embodiments, the supporting portion 41 may not be
provided.
Particularly, the part of the reflection structure 40, which is
inserted into the opening 30a of the molded material 30, may
contact an internal surface 30' of the opening 30a of the molded
material 30, and may extend to a bottom surface of the opening 30a
of the molded material 30 to contact the bottom surface (the first
lead 11 or the second lead 12) as illustrated in FIGS. 7 and 8.
Alternatively, the reflection structure 40 may not extend to the
bottom surface of the opening 30a of the molded material 30 and may
cover only part of the internal surface 30' of the opening 30a.
Including the above, various modifications of this embodiment are
possible.
After the structure wherein the package and the reflection
structure 40 are combined is prepared as described above, the first
resin layer 51 is formed to cover the light emitting element 20 as
illustrated in FIG. 8. A fluorescent material may be mixed into the
first resin layer 51. The first resin layer 51 may be cured and
prevent the reflection structure 40 from being separated from the
molded material 30. A light-transmitting second resin layer may be
provided on the first resin layer 51, if necessary.
Unlike the above, after the structure wherein the package and the
reflection structure 40 are combined is prepared as illustrated in
FIG. 7, the first resin layer 51 into which the fluorescent
material is mixed may not only fill the opening of the molded
material 30 to cover the light emitting element 20 but also be
formed such that a top surface of the first resin layer 51 is
higher than that of the molded material 30, without a second resin
layer being formed.
Alternatively, after the structure wherein the package and the
reflection structure 40 are combined is prepared as illustrated in
FIG. 7, a second resin layer may fill the opening 30a of the molded
material 30 to cover the light emitting element 20, and then a
first resin layer into which a fluorescent material is mixed may be
formed on the second resin layer.
The light emitting element package illustrated in FIG. 8 may be
understood to be a light emitting element package according to yet
another embodiment of the present invention.
Meanwhile, in the light emitting element package illustrated in
FIG. 8, since the reflection structure 40 contacts the first and
second leads 11 and 12, the first and second leads 11 and 12 need
to be insulated from each other. Accordingly, the reflection
structure 40 may have a radial shape and be divided into at least
two parts spaced apart from each other. A first part of the
reflection structure 40, which contacts the first lead 11, and a
second part of the reflection structure 40, which contacts the
second lead 12, may be spaced apart from each other, and have an
insulating material filled therebetween.
FIG. 9 is a partial schematic perspective view of a light emitting
element package according to yet another embodiment of the present
invention. Like the light emitting element package described above
with reference to FIG. 1, etc., in the light emitting element
package according to this embodiment, the reflection structure 40
includes the supporting portion 41 and a radial portion (not
shown).
The difference is that the supporting portion 41 contacts the
molded material 30 but is provided not continuously but discretely
along the circumference of the opening 30a of the molded material
30. That is, the supporting portion 41 has discontinuous parts 41a.
Two discontinuous parts 41a are illustrated in FIG. 9, but the
number of the discontinuous parts 41a may vary and the width of the
discontinuous parts 41a may be greater than that illustrated in
FIG. 9.
Since the supporting portion 41 serves to support the radial
portion (not shown), even when the supporting portion 41 has the
discontinuous parts 41a, manufacturing costs may be reduced,
without deteriorating heat radiation function and forward direction
luminance.
Alternatively, a supporting portion may not be part of the
reflection structure 40. That is, the supporting portion may be
part of the molded material 30, and the reflection structure 40 may
have the radial portion only. Even here, the supporting portion,
which is part of the molded material 30, may be provided not
continuously but discretely along the circumference of the opening
30a of the molded material 30.
FIG. 10 is a schematic perspective view of a light emitting element
package according to yet another embodiment of the present
invention, and FIG. 11 is an exploded perspective view of the light
emitting element package of FIG. 10. FIG. 12 is a schematic
cross-sectional view taken along line XII-XII of FIG. 10.
The light emitting element package according to this embodiment may
include a lead frame, a light emitting element 20, a molded
material 30, and a reflection structure 40, as illustrated in FIGS.
10 to 12.
The molded material 30 may include a supporting portion 33 provided
continuously or discretely along the circumference of the opening
30a. Particularly, the supporting portion 33 may be provided
adjacent to the exterior part of the opening 30a along the
circumference of the opening 30a. The supporting portion 33 is
illustrated to discretely surround the opening 30a of the molded
material 30 in FIGS. 10 to 12. However, the supporting portion 33
is not limited thereto and may continuously surround the opening
30a of the molded material 30 as described in the preceding
embodiments. If the supporting portion 33 discretely surrounds the
opening 30a of the molded material 30 as illustrated in FIGS. 10 to
12, this may be understood to be that recesses or concave and
convex portions are formed in the molded material 30.
For example, if the molded material 30 has an almost rectangular
parallelepiped shape, the opening 30a may be formed in the center
of a top surface of the molded material 30, and the light emitting
element 20 may be mounted at the central part of the opening 30a.
As illustrated in FIGS. 10 to 12, the supporting portion 33 may
extend along the circumference of the opening 30a of the molded
material 30 and protrude from corners of the molded material 30
along the positive z direction.
Here, a surface of the supporting portion 33, facing the opening
30a of the molded material 30 may be formed in a radial shape
extending radially relative to a direction along which light
generated by the light emitting element 20 emits (e.g., the
positive z direction). Particularly, the supporting portion 33 may
have an internal surface that has a downward inclination with
respect to the opening 30a of the molded material 30. This allows
the supporting portion 33 to more stably support the reflection
structure 40 that will be is described below. This also allows the
supporting portion 33 to more accurately guide or define a location
wherein the reflection structure 40 is combined.
A resin layer .[.60.]. .Iadd.50 .Iaddend.may be provided on the
light emitting element 20 in the opening 30a of the molded material
30 to cover the light emitting element 20 so as to protect the
light emitting element 20 from, for example, external moisture. A
fluorescent material may be mixed into the resin layer .[.60.].
.Iadd.50 .Iaddend.and the opening 30a of the molded material 30 may
be completely or partially filled with the resin layer .[.60.].
.Iadd.50.Iaddend.. The opening may be partially filled with the
resin layer .[.60.]. .Iadd.50 .Iaddend.into which the fluorescent
material is mixed, and a (transparent) filler having no fluorescent
material may be additionally provided to fill the remaining area.
The resin layer .[.60.]. .Iadd.50 .Iaddend.or the filler may
.[.be.]. fill not only the opening 30a of the molded material 30
but also fill the reflection structure 40 to a bottom end or a top
end, which will be described below.
The reflection structure 40 has an opening that corresponds to the
opening 30a of the molded material 30 and may contact the molded
material 30. As described above, if the supporting portion 33
discretely surrounds the opening 30a of the molded material 30,
that is, if it is understood that recesses or concave and convex
portions are formed in the molded material 30, the reflection
structure 40 may be fitted into the recesses or concave and convex
portions. The reflection structure 40 may include a metal having
excellent thermal conductivity. The reflection structure 40 may
also include a radial surface 45 formed in a radial shape extending
radially from the molded material relative to a direction along
which light generated by the light emitting element 20 emits.
When it comes to the role of the reflection structure 40, the
reflection structure 40 may be configured to reflect light emitted
by the light emitting element 20 such that the light proceeds
approximately along the positive z direction. Particularly, since
some of the light generated by the light emitting element 20
proceeds between the positive z direction and the positive y
direction, as well as along the positive z direction The luminance
in a forward direction of the light emitting element package may be
greatly increased and a beam angle of the light emitted by the
light emitting element package may be narrowed by having the above
described light reflected on the radial surface 45 of the
reflection structure 40 and then proceed approximately along the
positive z direction. That is, the radial surface 45 of the
reflection structure 40 together with .[.a.]. .Iadd.an
.Iaddend.inclined internal side surface of the opening 30a of the
molded material 30 may function as a reflective surface.
A reflective portion may be formed only of the internal side
surface of the opening 30a of the molded material 30, but there may
exist light that proceeds along a direction between the positive z
direction and the positive y direction without reaching the
internal side surface of the opening 30a of the molded material 30.
In the light emitting element package according to this embodiment,
the above described light may also be reflected on the radial
surface 45 provided outside the molded material 30 and then proceed
approximately along the positive z direction.
The cross-section of the radial surface 45 of the reflection
structure 40 may be flat or bent. For example, referring to FIG.
12, the cross-section of the radial surface 45 of the reflection
structure 40 may be flat. That is, the radial surface 45 of the
reflection structure 40 may form a predetermined angle a with a
main emission direction along which light generated by the light
emitting element 20 emits. Here, the main emission direction refers
to the positive z direction. Here, the predetermined angle a may be
equal to or greater than 10.degree. and equal to or less than
20.degree..
Meanwhile, FIG. 13 is a schematic cross-sectional view of a light
emitting element package according to yet another embodiment of the
present invention. FIG. 13 is a cross-sectional view of the light
emitting element package according to the present invention, taken
along a line located similar to the line XII-XII of FIG. 10.
Referring to FIG. 13, the radial surface 45 of the reflection
structure 40 may form a first angle a1 with the positive z
direction from a point where the radial surface contacts the molded
material 30 to a first point 43 away from the molded material 30,
and form a second angle a2 from the first point 43 to a second
point 44 further away from the molded material 30 compared to the
first point 43. Here, the second angle a2 may be greater than the
first angle a1. Particularly, the first angle a1 may be about
10.degree. and the second angle a2 may be about 20.degree..
Here, the second point 44 may be, for example, an end portion of
the reflection structure 40. That is, the first point 43 may be a
certain point between two end portions of an internal surface of
the reflection structure 40, located along the positive z
direction, i.e., between an end portion along a direction toward
the molded material 30 (the negative z direction) and an end
portion along an emission direction of light (the positive z
direction). In addition, each of the first and second points 43 and
44 may be continuously provided along the circumference of the
opening 30a of the molded material 30 to form an encircling
line.
Since the radial surface 45 is inclined by the predetermined angle
a as described above, light emitted from the light emitting element
20 may be radiated onto the radial surface 45. Accordingly, a beam
angle of light emitted from the light emitting element package may
be narrowed. The radial surface 45 of the reflection structure 40
may be coated with a reflective material such as silver to improve
reflectivity. For convenience, portions other than the radial
surface 45 may also be coated.
The reflection structure 40 may have a shape that corresponds to
the supporting portion 33, thereby contacting the molded material
30. For example, if the supporting portion 33 is continuously
provided, the reflection structure 40 may also have a continuous
shape that corresponds to the shape of the supporting portion 33.
Another example would be that if the supporting portion 33 is
discretely provided as illustrated in FIGS. 10 and 11, the
reflection structure 40 may also have a discrete shape to be
inserted between the supporting portions 33.
FIG. 14 is a schematic cross-sectional view showing paths of light
emitted from the light emitting element package according to
embodiments of the present invention. Although FIG. 14
schematically illustrates paths of light emitted from the light
emitting element package illustrated in FIG. 12, the paths of light
may be equally or similarly applied to the light emitting element
package illustrated in FIG. 13.
Referring to FIG. 14, light emitted from the light emitting element
20 may directly reach area A of a illuminated surface 70 along a
first path 21, reach area B of the illuminated surface 70 after
being reflected on the molded material 30 along a second path 22,
and reach area C of the illuminated surface 70 after being
reflected on the reflection structure 40 along a third path 23.
Here, if the reflection structure 40 and the molded material 30
have the same reflectivity, the luminance of area A may be the
highest, the luminance of area B may be the second highest, and the
luminance of area C may be the lowest. That is, the luminance is
lowered away from an optical axis. In particular, the luminance may
be greatly lowered from area B to area C.
However, according to the embodiments of the present invention, the
reflection structure 40 may have a higher reflectivity than that of
the molded material 30. For example, as described above, the
reflection structure 40 may include a metal and thus have a higher
reflectivity than that of the molded material 30 that is formed of
a resin material. Accordingly, the luminance of light projected
onto area C along the third path 23 may increase compared to a
conventional way due to the high reflectivity of the reflection
structure 40. Therefore, the luminance may not be rapidly reduced
but gradually reduced from area A to area C and, particularly, the
change in the luminance may be gradual or almost no change may
occur from area B to area C. As such, light having an almost
uniform luminance may be effectively projected onto the whole
illuminated surface 70.
FIG. 15 is a schematic graph showing a beam angle of light emitted
from the light emitting element package according to embodiments of
the present invention.
A conventional light emitting element package has a peak of optical
power in an optical axis direction, and emits light in such a
manner that the optical power is not rapidly but gradually reduced
as an angle with the optical axis is increased. Furthermore, due to
a large beam angle, the conventional light emitting element package
has a small amount of reduction in optical power even considerably
far away from an optical axis, and thus is used for lighting by
having an overall luminance of light emitted from a light emitting
element package be gradually reduced over a wide range.
According to embodiments of the present invention, however, as
shown in FIG. 15, light emitted from the light emitting element 20
may be reflected by the reflection structure 40 and thus the
optical power near an optical axis may be almost uniform even away
from the optical axis. Furthermore, the luminance of an illuminated
area may be increased by narrowing a beam angle. Thus, light
emitted from the light emitting element package may have a uniform
and high luminance near the optical axis even away from the optical
axis. As such, when the light emitting element package is used as a
flash for a mobile phone, a camera, etc., light having a high and
uniform luminance may be effectively projected onto a whole area to
be photographed. That is, the above-described optical lenses are
for a flash and may be combined with the light emitting element
package to effectively project light having a uniform intensity
onto an illuminated area.
FIG. 16 is a partial schematic perspective view of a light emitting
element according to yet another embodiment of the present
invention. Hereinafter, an adhesive layer 60 will be described with
reference to FIGS. 12, 13, and 16. The adhesive layer 60 may be
provided at least part of a region between the molded material 30
and the reflection structure 40 to fix the reflection structure 40
onto the molded material 30.
The adhesive layer 60 may be provided between the supporting
portion 33 of the molded material 30 and the reflection structure
40 as illustrated in FIG. 12. That is, it would be preferable that
an exposed portion of the adhesive layer 60 is minimized and, due
to a low reflectivity of light, the adhesive layer 60 may not be
exposed between the radiation surface 45 of the reflection
structure 40 and the opening 30a of the molded material 30.
Accordingly, as illustrated in FIGS. 12 and 13, the adhesive layer
60 may be provided between the supporting portion 33 and the
reflection structure 40, and may not be provided between the
reflection structure 40, and may not be provided between the
reflection structure 40 and part of the molded material 30 that is
adjacent to the opening 30a. .Iadd.Therefore, the adhesive layer 60
is not exposed to the opening 40a (refer to FIG. 1) of the
reflection structure 40 and the opening 30a of the molded material
30. .Iaddend.
Referring to FIG. 12, the thickness of the adhesive layer 60 may
vary according to locations, to maximize adhesive force while
minimizing the amount of the adhesive layer. Particularly, a first
thickness .[.51.]. .Iadd.61 .Iaddend.in an area adjacent to the
light emitting element 20 may be greater than a second thickness
.[.52.]. .Iadd.62 .Iaddend.in an area away from the light emitting
element 20. Here, the thickness of the adhesive layer 60 may be
gradually reduced away from the light emitting element 20.
Generally, heat is generated from the light emitting element 20 in
the light emitting element package and areas adjacent to the light
emitting element 20 is greatly influenced by heat generated from
the light emitting element 20. Accordingly, the adhesive layer 60
may have a sufficiently large thickness in areas adjacent to the
light emitting element 20, thereby ensuring a strong adhesion
between the molded material 30 and the reflection structure 40, and
have a reduced thickness in areas away from the light emitting
element 20, thereby reducing the amount of material used to
manufacture the light emitting element package and manufacturing
costs.
Meanwhile, according to another embodiment of the present
invention, a light emitting element package may include a lead
frame, a light emitting element 20, a molded material 30, a
reflection structure 40, and an adhesive layer 60. The light
emitting element package according to this embodiment is the same
as or similar to the light emitting element package according to
the preceding embodiments. Thus, repeated description thereof will
be omitted.
The molded material 30 may be combined with the lead frame and have
the opening 30a for emitting light generated by the light emitting
element 20. That is, unlike the molded material 30 according to the
preceding embodiments, the molded material 30 according to this
embodiment may not include the supporting portion 33.
The reflection structure 40 may have an opening that corresponds to
the opening 30a of the molded material 30, and contact the molded
material 30. The reflection to structure 40 according to this
embodiment is the same as or similar to the reflection structure 40
according to the preceding embodiments, but may optionally have a
shape that corresponds to the supporting portion 33.
The adhesive layer 60 may be provided at least partly between the
molded material 30 and the reflection structure 40 to fix the
reflection structure 40 onto the molded material 30. The first
thickness .[.51.]. .Iadd.61 .Iaddend.of the adhesive layer 60 in
areas adjacent to the light emitting element 20 may be greater than
the second thickness .[.52.]. .Iadd.62 .Iaddend.of the adhesive
layer 60 in areas away from the light emitting element 20. The
adhesive layer 60 according to this embodiment is the same as or
similar to the adhesive layer 60 according to the preceding
embodiments, and thus a detailed description thereof will be
omitted. The adhesive layer 60 is used to maintain adhesive
force.
FIG. 17 is a schematic side elevation view of a backlight unit
according to an embodiment of the present invention.
As illustrated in FIG. 17, the backlight unit according to this
embodiment includes a frame 110, a reflective sheet 115 on part of
the frame 110, a light guide plate 120 on the reflective sheet 115,
and a light emitting element package 100 on other part of the frame
110 and configured to illuminate the light guide plate 120. The
light emitting element package 100 may be any one of the light
emitting element packages according to the preceding embodiments
and modifications thereof. The light emitting element package 100
may be connected to a printed circuit board 112.
According to his embodiment, since the light emitting element
package 100 included in the backlight unit has improved heat
radiation function and forward direction luminance, the whole
backlight unit may have improved heat radiation function and
improved luminance of emitted light.
Although the light emitting element package 100 is illustrated to
be provided on a side surface of the light guide plate 120 in FIG.
17, the present invention is not limited thereto and but applicable
to a direct-type backlight unit in which a light guide plate is
provided on or above a reflective sheet and a light emitting
element package is provided under or below the light guide
plate.
While the present invention has been described with reference to
embodiments illustrated in the drawings, it will be understood by
those of ordinary skill in the art that various changes in form and
details may be made without departing from the spirit and scope of
the present invention as as set forth in the following claims.
INDUSTRIAL APPLICABILITY
The present invention may be used to manufacture a light emitting
element package having excellent heat radiation performance and
high luminance, and a backlight unit including the same.
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