U.S. patent application number 14/336055 was filed with the patent office on 2015-04-02 for light emitting diode package.
The applicant listed for this patent is Lextar Electronics Corporation. Invention is credited to Che-Ming HSU, Liang-Ta LIN, Wen-Kai SHAO.
Application Number | 20150091034 14/336055 |
Document ID | / |
Family ID | 52632237 |
Filed Date | 2015-04-02 |
United States Patent
Application |
20150091034 |
Kind Code |
A1 |
HSU; Che-Ming ; et
al. |
April 2, 2015 |
LIGHT EMITTING DIODE PACKAGE
Abstract
A light-emitting diode (LED) package structure includes a lead
frame, a LED chip, a package body, N opaque spacer and N+1
encapsulating glues. The LED chip is disposed on the lead frame;
the package body covers the lead frame and exposes the LED chip.
The package body has an accommodation space, divided by the N
opaque spacers disposed on the LED chip into N+1 chambers. The N+1
encapsulating glues are filled into the N+1 chambers, where N is a
natural number.
Inventors: |
HSU; Che-Ming; (Dacheng
Township, TW) ; SHAO; Wen-Kai; (New Taipei City,
TW) ; LIN; Liang-Ta; (Guishan Township, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Lextar Electronics Corporation |
Hsinchu |
|
TW |
|
|
Family ID: |
52632237 |
Appl. No.: |
14/336055 |
Filed: |
July 21, 2014 |
Current U.S.
Class: |
257/98 |
Current CPC
Class: |
H01L 33/504 20130101;
H01L 33/60 20130101 |
Class at
Publication: |
257/98 |
International
Class: |
H01L 33/50 20060101
H01L033/50; H01L 33/56 20060101 H01L033/56 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 27, 2013 |
TW |
102135095 |
Claims
1. A light emitting diode package, comprising: a lead frame
comprising a die bonding area; a package body covering the lead
frame and exposing part of the lead frame, wherein a top surface of
the package body has an opening and an accommodation space concaved
from the opening, wherein the accommodation space comprises a
bottom surface and a sidewall surrounding the bottom surface and
exposing the die bonding area of the lead frame on the bottom
surface of the accommodation space; a light emitting diode chip
emitting a first light in a wavelength .lamda..sub.1 mounted on the
die bonding area, and the light emitting diode chip having a light
emitting surface facing the opening; N opaque spacers vertically
spaced and across disposed in the light emitting surface of the
light emitting diode chip, dividing the light emitting surface into
N+1 parts and dividing the accommodation space into N+1 chambers,
wherein each of the chambers exposes a part of the light emitting
surface of the light emitting diode chip; and N+1 encapsulating
glues separately filling into each of the chamber, and the i.sup.th
encapsulating glue comprising an i.sup.th wavelength converting
material, wherein i and N are both natural numbers, and
1.ltoreq.i.ltoreq.N+1.
2. The light emitting diode package of claim 1, wherein the
i.sup.th wavelength converting material in the i.sup.th
encapsulating glue and the j.sup.th wavelength converting material
in the j.sup.th encapsulating glue belong to the same kind but
different concentrations, wherein j is a natural number, and
1.ltoreq.j.ltoreq.N1, but i.noteq.j.
3. The light emitting diode package of claim 1, wherein the
i.sup.th wavelength converting material in the i.sup.th
encapsulating glue is different from a j.sup.th wavelength
converting material in a j.sup.th encapsulating glue, wherein j is
a natural number, and 1.ltoreq.j.ltoreq.N+1, but i.noteq.j.
4. The light emitting diode package of claim 1, wherein each of the
opaque spacer extends from the bottom surface of the accommodation
space to the opening along the sidewall, such that the
encapsulating glue in the neighboring chambers is not mixed to each
other.
5. The light emitting diode package of claim 1, wherein the opaque
spacers comprises a silicone or an epoxy blended with the high
reflectivity material.
6. The light emitting diode package of claim 5, wherein the bottom
surface and the sidewall also comprise a high reflectivity
material.
7. The light emitting diode package of claim 6, wherein the high
reflectivity material is selected from the group consisting of
titanium dioxide, silicon dioxide, aluminum oxide and combinations
thereof.
8. The light emitting diode package of claim 1, wherein the first
light emitted by the light emitting diode chip, after passing
through the i.sup.th chamber, is converted to a i+1th light in a
wavelength i+1, in which .lamda.i+1>.lamda..sub.1, by the
i.sup.th wavelength converting material in the encapsulating glue
in the i.sup.th chamber, to emit a plurality of fluorescence which
is configured to be mixed to a white light.
9. The light emitting diode package of claim 1, wherein the light
emitting diode chip is an ultraviolet light emitting diode chip or
a blue light emitting diode chip.
10. The light emitting diode package of claim 9, the wavelength
converting material is a phosphor, pigment, dye, or combinations
thereof.
Description
RELATED APPLICATIONS
[0001] This application claims priority to Taiwan Application
Serial Number 102135095, filed Sep. 27, 2013, which is herein
incorporated by reference.
BACKGROUND
[0002] 1. Field of Invention
[0003] The present invention relates to a light emitting diode
package. More particularly, the present invention relates to a
light emitting diode package which separates encapsulating
glues.
[0004] 2. Description of Related Art
[0005] A plastic leaded chip carrier (PLCC) light emitting diode
package includes one or more light emitting diode chip in a package
sealed with an encapsulating glue. With light emitting diode chips
or phosphors of different color in the encapsulating glue, such as
a blue light emitting diode chip form white light with yellow
phosphors, the PLCC is able to emit a desired light color.
[0006] However, because the phosphors of different colors are all
in the same accommodation space, light excited by the respective
phosphors may be absorbed by another phosphor. Therefore a light
absorbance effect may be observed between these phosphors
configured to excite different color of light, which not only
consumes energy but also lowers the color rendering index (CRI)
value.
SUMMARY
[0007] Therefore, a light emitting diode package which can separate
encapsulating glues is provided. The package provides various
accommodation spaces to separate different kinds of encapsulating
glues in a packaging process. The package let a wavelength transfer
substance, for example, phosphor, may exist alone to prevent the
energy consumption by the absorbance effect and have higher CRI
value and brightness. Also, the package only use one light emitting
diode chip, which can save costs and enhance a process fabricating
convenience.
[0008] One aspect of the present disclosure is a light emitting
diode package, including a lead frame comprising a die bonding
area. A package body covering the lead frame and exposing part of
the lead frame, wherein a top surface of the package body has an
opening and an accommodation space concaved from the opening,
wherein the accommodation space includes a bottom surface and a
sidewall surrounding the bottom surface, and exposing the die
bonding area of the lead frame on the bottom surface of the
accommodation space. A light emitting diode chip emitting a first
light in a wavelength .lamda..sub.1 mounted on the die bonding
area, and the light emitting diode chip having a light emitting
surface facing the opening. N opaque spacers vertically spaced and
across disposed in the light emitting surface of the light emitting
diode chip, dividing the light emitting surface into N+1 parts and
dividing the accommodation space into N+1 chambers, and the each of
the chambers exposes a part of the light emitting surface of the
light emitting diode chip. And N+1 encapsulating glues separately
filling into each of the chamber, and the i.sup.th encapsulating
glue comprising an i.sup.th wavelength converting material, wherein
i and N are both natural numbers, and 1.ltoreq.i.ltoreq.N+1.
[0009] According to one embodiment of the present disclosure,
wherein the i.sup.th wavelength converting material in the i.sup.th
encapsulating glue and the j.sup.th wavelength converting material
in the j.sup.th encapsulating glue belong to the same kind but
different concentrations, wherein j is a natural number, and
1.ltoreq.j.ltoreq.N+1, but i.noteq.j.
[0010] According to one embodiment of the present disclosure,
wherein the i.sup.th wavelength converting material in the i.sup.th
encapsulating glue is different from a j.sup.th wavelength
converting material in a j.sup.th encapsulating glue, wherein j is
a natural number, and 1.ltoreq.j.ltoreq.N+1, but i.noteq.j.
[0011] According to one embodiment of the present disclosure,
wherein each of the opaque spacer extends from the bottom surface
of the accommodation space to the opening along the sidewall, such
that the encapsulating glue in the neighboring chambers is not
mixed to each other.
[0012] According to one embodiment of the present disclosure,
wherein the opaque spacers comprises a silicone or an epoxy blended
with the high reflectivity material.
[0013] According to one embodiment of the present disclosure,
wherein the bottom surface and the sidewall also comprise the high
reflectivity material.
[0014] According to one embodiment of the present disclosure,
wherein the high reflectivity material is selected from the group
consisting of titanium dioxide, silicon dioxide, aluminum oxide and
combinations thereof.
[0015] According to one embodiment of the present disclosure,
wherein the first light emitted by the light emitting diode chip,
after passing through the i.sup.th chamber, is converted to a i+1th
light in a wavelength i+1, in which .lamda.i+1>.lamda..sub.1, by
the i.sup.th wavelength converting material in the encapsulating
glue in the i.sup.th chamber, to emit a plurality of fluorescence
which is configured to be mixed to a white light.
[0016] According to one embodiment of the present disclosure,
wherein the light emitting diode chip is an ultraviolet light
emitting diode chip or a blue light emitting diode chip.
[0017] According to one embodiment of the present disclosure, the
wavelength converting material is a phosphor, pigment, dye, or
combinations thereof.
[0018] It is to be understood that both the foregoing general
description and the following detailed description are by examples,
and are intended to provide further explanation of the disclosure
as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The disclosure can be more fully understood by reading the
following detailed description of the embodiment, with reference
made to the accompanying drawings as follows:
[0020] FIG. 1 is a stereogram of light emitting diode package;
[0021] FIG. 2 is a schematic diagram of light emitting diode
package;
[0022] FIG. 3 is a schematic diagram of light emitting diode
package; and
[0023] FIG. 4 is a photoluminescence diagram according to one
embodiment of this disclosure.
DETAILED DESCRIPTION
[0024] Reference will now be made in detail to the present
embodiments of the disclosure, examples of which are illustrated in
the accompanying drawings. Wherever possible, the same reference
numbers are used in the drawings and the description to refer to
the same or like parts.
[0025] Referring to FIG. 1, FIG. 1 is a stereogram of light
emitting diode package. As shown in FIG. 1, a light emitting diode
package 100 includes a lead frame 110, a package body 120, a light
emitting diode chip 130, and opaque spacers 140. More particularly,
the light emitting diode package 100 includes a lead frame 110, a
top surface of the lead frame 110 having a die bonding area 120.
The lead frame 110 is covered by the package body 120, and exposed
part of the lead frame 110 and the die bonding area 120 from the
package body 120. A top surface of the package body 120 has an
opening 122, and an accommodation space 124 concaved from the
opening 122. The accommodation space includes a bottom surface 126
and a sidewall 128 surrounding the bottom surface 126. The die
bonding area 112 is exposed on the bottom surface 126 of the
accommodation space 124. A light emitting diode chip 130 is mounted
on the die bonding area 112. The light emitting diode chip 130 has
a light emitting surface 132 facing the opening 122 of the
accommodation space 124, and can emit a first light in a wavelength
.lamda..sub.1. An opaque spacer 140 is vertically spaced and across
disposed in the light emitting surface 132 of the light emitting
diode chip 130. The opaque spacer 140 is vertically spaced and
across disposed in the light emitting surface 132, dividing the
light emitting surface 132 into two parts, and dividing the
accommodation space 124 into a first chamber 150A and a second
chamber 150B. Both chambers 150A, 150B expose part of the light
emitting surface 132 of the light emitting diode chip 130.
[0026] More particularly, in one embodiment of the present
disclosure, the opaque spacer 140 extends from the bottom surface
126 of the accommodation space 124 to the opening 122 along the
sidewall 128, separating a encapsulating glue 160 in the
neighboring chambers 150, making the different kinds of
encapsulating glues not be mixed. The opaque spacer 140 includes a
silicone or an epoxy blended with a high reflectivity material. The
bottom surface 126 and the sidewall 128 also include the high
reflectivity material. The high reflectivity material is selected
from the group consisting of titanium dioxide, silicon dioxide,
aluminum oxide and combinations thereof.
[0027] FIG. 2 is referred to, or together with FIG. 1, for clearly
understanding the present disclosure. FIG. 2 is the cross-section
view of section line AA' of the light emitting diode package 100 in
FIG. 1. As shown in FIG. 2, a first encapsulating glue 160A is
filled into the first chamber 150A. The first encapsulating glue
160A includes a first wavelength converting material 170A. A second
encapsulating glue 160B is filled into the second chamber 150B. The
second encapsulating glue 160B includes a second wavelength
converting material 170B. The first wavelength converting material
170A can convert the first light in the wavelength .lamda..sub.1
emitted from the light emitting diode chip 130 into a second light
in a wavelength .lamda..sub.2. The second wavelength converting
material 170B can convert the first light in the wavelength
.lamda..sub.1 emitted from the light emitting diode chip 130 into a
third light in a wavelength .lamda..sub.3. The second light and the
third light can mix and form a white light. In one embodiment of
the present disclosure, the light emitting diode chip 130 is a blue
light emitting diode chip, the first wavelength converting material
170A is red phosphor, and the second wavelength converting material
170B is green phosphor. The light emitted from the light emitting
diode chip is converted and mixed after passing through different
chambers to form the white light. In one embodiment of the present
disclosure, the light emitting diode chip 130 is a blue light
emitting diode chip, red light emitting diode chip, green light
emitting diode chip, or the ultraviolet light emitting diode chip.
The wavelength converting material is phosphor, pigment, dye,
and/or combinations thereof.
[0028] Referring to FIG. 3, FIG. 3 shows a cross-section scheme of
a light emitting diode package according one embodiments of the
present disclosure. The basic structures in the embodiment is the
same as the embodiments in FIG. 2, which includes a lead frame 310,
a die bonding area 312 on a top surface of the lead frame 310, a
light emitting diode chip 330 mounted on the die bonding area 312,
and the light emitting diode chip 330 having a light emitting
surface 332 on a top surface. A package body 320 covers the lead
frame 310, and exposes part of the lead frame 310, the die bonding
area 312 and the light emitting diode chip 330 mounted on the die
bonding area 312. A top surface of the package body 320 has an
opening 322, and an accommodation space 324 concaved from the
opening 322. The accommodation space 324 includes a bottom surface
326 and a sidewall 328 surrounding the bottom surface 326. The
light emitting diode chip 330 is on the bottom surface 326 of the
accommodation space 324. The light emitting surface 332 of the
light emitting diode chip 330 faces the opening 322 of the package
body 320.
[0029] Referring to FIG. 3, the difference of the two embodiments
in the FIG. 3 and FIG. 2 is two opaque spacers 340 disposed on the
light emitting surface 332 of the light emitting diode chip 330
including a first opaque spacer 340A and a second opaque spacer
340B. The two opaque spacers 340 are vertically spaced and across
disposed in the light emitting surface 332, dividing the
accommodation space 324 into three chambers 350, including a first
chamber 350A, a second chamber 350B, and a third chamber 350C. The
all three chambers 350 expose part of the light emitting surface
332 of the light emitting diode chip 330. More particularly, in one
embodiment of the present disclosure, the opaque spacers 340 extend
from the bottom surface 326, along the sidewall 328, of the
accommodation space 324 to the opening 322, separating a
encapsulating glue 360 in the neighboring chambers 350, making the
different kinds of encapsulating glues not be mixed. The opaque
spacer 340 includes a silicone or an epoxy blended with a high
reflectivity material. In which the high reflectivity material is
selected from the group consisting of titanium dioxide, silicon
dioxide, aluminum oxide and combinations thereof. The bottom
surface 326 and the sidewall 328 also include the high reflectivity
material.
[0030] Referring to FIG. 3, in one embodiments of the present
disclosure, a first encapsulating glue 360A is filled into the
first chamber 350A. The first encapsulating glue 360A includes a
first wavelength converting material 370A. A second encapsulating
glue 360B is filled into the second chamber 350B. The second
encapsulating glue 360B includes a second wavelength converting
material 370B. A third encapsulating glue 360C is filled into the
third chamber 350C. The third encapsulating glue 360C includes a
third wavelength converting material 370C. The first wavelength
converting material 370A can convert the first light in the
wavelength .lamda..sub.1 emitted from the light emitting diode chip
330 into a second light in a wavelength .lamda..sub.2. The second
wavelength converting material 370B can convert the first light in
the wavelength .lamda..sub.1 emitted from the light emitting diode
chip 330 into a third light in a wavelength .lamda..sub.3. The
third wavelength converting material 370C can convert the first
light in the wavelength .lamda..sub.1 emitted from the light
emitting diode chip 330 into a fourth light in a wavelength
.lamda..sub.4. And the second light, the third light, and the
fourth light can mix and form a white light. In one embodiment of
the present disclosure, the light emitting diode chip 330 is an
ultraviolet light emitting diode chip, the first wavelength
converting material 370A is red phosphor, the second wavelength
converting material 370B is green phosphor, and the third
wavelength converting material 370C is blue phosphor. In one
embodiment of the present disclosure, the light emitting diode chip
330 is a blue light emitting diode chip, red light emitting diode
chip, green light emitting diode chip, or the ultraviolet light
emitting diode chip. The wavelength converting material is
phosphor, pigment, dye, and/or combinations thereof.
[0031] The light emitting diode package in FIGS. 1-3 are all
schematic diagrams, in which the shape of the package body and the
lead frame may change to comply the package structure or
fabricating process needed, also may use on the ready-made light
emitting diode package. The useful point of the present disclosure
is by disposing the opaque spacer on the light emitting diode chip
to divide the accommodation space into different chambers to fill
the different wavelength converting material separately in to the
different chambers. Making the exciting and converting process of
the different light color may not be affected by the other kinds of
wavelength converting material. The white light formed by mixing
the different color lights therefore can increase the brightness
and CRI value. Also, the number of the opaque spacers is not
limited to one or two in the embodiments shown in figures, can
further add for demand.
[0032] According to some embodiments of the present disclosure, N
opaque spacers may be disposed on the light emitting diode chip,
and vertically spaced and across disposed in the light emitting
surface of the light emitting diode chip. Which divide the light
emitting surface into N+1 parts and the accommodation space into
N+1 chambers, in which each of the chambers exposes part of the
light emitting surface of the light emitting diode chip. And N+1
encapsulating glues are filled into the N+1 chambers, separately.
The i.sup.th encapsulating glue of the N+1 encapsulating glues
includes a i.sup.th wavelength converting material. I and N are
both natural numbers, and 1.ltoreq.i.ltoreq.N+1. For example, as
embodiment in FIG. 2, N=1, as embodiment in FIG. 3, N=2. The light
emitting diode chip may be a blue light emitting diode chip or an
ultraviolet light emitting diode chip.
[0033] According to some embodiments of the present disclosure,
wherein the i.sup.th wavelength converting material in the i.sup.th
encapsulating glue and the j.sup.th wavelength converting material
in the j.sup.th encapsulating glue belong to the same kind but
different concentrations, or the i.sup.th wavelength converting
material in the i.sup.th encapsulating glue is different from the
j.sup.th wavelength converting material in the j.sup.th
encapsulating glue, wherein j is a natural number, and
1.ltoreq.j.ltoreq.N+1, but i.noteq.j. And the i.sup.th and j.sup.th
wavelength converting material are phosphor, pigment, dye, and/or
combinations thereof.
[0034] Referring to FIG. 4, FIG. 4 is a photoluminescence diagram
according to one embodiment of this disclosure. As shown in FIG. 4,
line B depicts a photoluminescence experiment result of two
phosphors filled into two different chambers, separately, and line
A depicts a photoluminescence experiment result of two phosphors
mixed and filled into one accommodation space. The line B has more
turning points than line A. The differences of the turning points
shows that the white light formed in line B is much similar to a
white light mixed by two light sources, therefore has better CRI
value. Table 1 is the average CRI value averaged from 8 experiment
results.
TABLE-US-00001 TABLE 1 R1 R2 R3 R4 R5 R6 R7 R8 CRI Exper- 80.85
88.65 94.33 80.75 80.23 84.03 85.87 65.33 82.50 iment A Exper-
88.30 90.71 91.73 88.77 87.27 87.70 89.37 75.50 87.42 iment B
[0035] The experiment data in table 1 is in consistent with FIG. 4.
The phosphors separating light emitting diode package according to
various embodiments of the present disclosure has better CRI value
in comparison with the package mixing two phosphors in one
accommodation space.
[0036] According to various embodiments of the present disclosure,
the light emitting diode package has following advantages including
the CRI value and the brightness of the formed white light can be
increased by separating different wavelength converting material to
avoid the energy absorbance effect between different kinds of the
wavelength converting material. Also the light emitting diode
package in the present disclosure only include one light emitting
diode chip, not only can save the cost of other light emitting
diode chips, but also can enhance the convenience of fabricating
process. No matter what the package substrate is, only add an
opaque spacer on the light emitting diode chip can form the same
package according to the present disclosure. Therefore no new mold
need to make and no limitation of the shape of the opaque spacer.
Different kinds of wavelength converting material can be filled
into different chambers in one process. The provided light emitting
diode package is not only easy to fabricate, but also can lower the
cost. The light emitting diode package can also reapply by
replacing the wavelength converting material in the package. The
brightness and the CRI value can both be enhanced by the provided
light emitting diode structure.
[0037] Although the present disclosure has been described in
considerable detail with reference to certain embodiments thereof,
other embodiments are possible. Therefore, the spirit and scope of
the appended claims should not be limited to the description of the
embodiments contained herein.
[0038] It will be apparent to those skilled in the art that various
modifications and variations can be made to the structure of the
present disclosure without departing from the scope or spirit of
the disclosure. In view of the foregoing, it is intended that the
present disclosure cover modifications and variations of this
disclosure provided they fall within the scope of the following
claims.
* * * * *