U.S. patent application number 11/325327 was filed with the patent office on 2006-08-17 for led housing and fabrication method thereof.
This patent application is currently assigned to Samsung Electro-Mechanics Co., Ltd.. Invention is credited to Kyung Taeg Han, Bum Joon Jin, Chang Wook Kim, Seon Goo Lee.
Application Number | 20060180925 11/325327 |
Document ID | / |
Family ID | 36814851 |
Filed Date | 2006-08-17 |
United States Patent
Application |
20060180925 |
Kind Code |
A1 |
Lee; Seon Goo ; et
al. |
August 17, 2006 |
LED housing and fabrication method thereof
Abstract
The invention relates to an LED housing and its fabrication
method. In the LED housing, a heat conducting part has a chip
mounting area, a heat connecting area opposed to the chip mounting
area and a groove formed adjacent to the heat connecting area. An
electrical connecting part has a wiring area placed adjacent to the
chip mounting area and an external power connecting area led to the
wiring area. A housing body is made of molding resin, and
integrally holds the heat conducting part and the electrical
connecting part while isolating the electrical connecting part from
the heat conducting part. The housing body is provided with a
recess extended from a portion of the groove of the heat conducting
part to a side of the housing body. In this fashion, the invention
can overcome restricted application problems by isolating the
electrical connecting parts from the heat conducting part.
Inventors: |
Lee; Seon Goo; (Gunpo,
KR) ; Jin; Bum Joon; (Osan, KR) ; Han; Kyung
Taeg; (Hwasung, KR) ; Kim; Chang Wook;
(Anyang, KR) |
Correspondence
Address: |
LOWE HAUPTMAN BERNER, LLP
1700 DIAGONAL ROAD
SUITE 300
ALEXANDRIA
VA
22314
US
|
Assignee: |
Samsung Electro-Mechanics Co.,
Ltd.
Suwon
KR
|
Family ID: |
36814851 |
Appl. No.: |
11/325327 |
Filed: |
January 5, 2006 |
Current U.S.
Class: |
257/717 ;
257/E33.073 |
Current CPC
Class: |
H01L 33/642 20130101;
H01L 33/647 20130101; H01L 2224/48247 20130101; H01L 2224/48091
20130101; H01L 2924/00014 20130101; H01L 2924/01019 20130101; H01L
33/62 20130101; H01L 2924/12041 20130101; H01L 33/486 20130101;
H01L 2224/48091 20130101 |
Class at
Publication: |
257/717 |
International
Class: |
H01L 23/34 20060101
H01L023/34 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 17, 2005 |
KR |
10-2005-0013248 |
Claims
1. A light emitting diode housing comprising: a heat conducting
part having a chip mounting area to be mounted with a light
emitting diode chip, a heat connecting area opposed to the chip
mounting area and a groove formed adjacent to the heat connecting
area; an electrical connecting part having a wiring area placed
adjacent to the chip mounting area of the heat conducting part and
an external power connecting area led to the wiring area; and a
housing body made of molding resin, and integrally holding the heat
conducting part and the electrical connecting part while isolating
the electrical connecting part from the heat conducting part,
wherein the housing body is provided with a recess extended from a
portion of the groove of the heat conducting part to a side of the
housing body.
2. The light emitting diode housing according to claim 1, wherein
the electrical connecting part comprises a pair of lead to be
connected with the light emitting diode chip by wires,
respectively.
3. The light emitting diode housing according to claim 1, wherein
the heat conducting part is electrically connected to the light
emitting diode chip.
4. The light emitting diode housing according to claim 1, wherein
the chip mounting area has at outer peripheral portion extended in
a light emitting direction forming into a reflector.
5. The light emitting diode housing according to claim 1, wherein
the housing body is configured to expose the chip mounting area and
the heat connecting area of the heat conducting part and the wiring
area of the electrical connecting part.
6. The light emitting diode housing according to claim 5, wherein
the housing body has a peripheral portion formed around and
extended beyond the chip mounting area of the heat conducting part
and the wiring area of the electrical connecting part, thereby
forming a recess therein.
7. The light emitting diode housing according to claim 1, wherein
the heat conducting part further comprises a neck formed along an
outer peripheral portion between the chip mounting area and the
groove.
8. A fabrication method of a light emitting diode housing,
comprising steps of: (a) preparing a heat conducting part having a
chip mounting area, a heat connecting area opposed to the chip
mounting area and a groove formed adjacent to the heat connecting
area; (b) machining a sheet metal to prepare a frame having an
outer periphery, at least one electrical connecting part and a
plurality of holders extended from the outer periphery to the
center of the frame and a hole formed in the outer periphery; (c)
inserting distal ends of the holders into the groove and placing a
distal end of the electrical connecting part having the wiring area
adjacent to the chip mounting area of the heat conducting part to
assemble the heat conducting part to the frame; (d) mounting a
resultant structure of the heat conducting part and the frame to a
mold; (e) injecting resin into the mold to form a housing body
integrally holding the heat conducting part, the electrical
connecting part and the holders, with a portion of the electrical
connecting part and the holders being exposed in part, while
isolating the heat conducting part from the electrical connecting
part; and (f) cutting the electrical connecting part from the frame
and separating the holders from the heat conducting part.
9. The fabrication method according to claim 8, wherein the
machining step (b) comprises punching.
10. The fabrication method according to claim 8, wherein the
machining step (b) comprises bending the electrical connecting
part.
11. The fabrication method according to claim 8, wherein the
machining step (b) comprises bending the holders, the method
further comprising a step of: (g) bending the electrical connecting
part after the cutting step (f).
12. The fabrication method according to claim 8, wherein the
inserting step (c) comprises arranging the distal ends of the
holders opposite to each other and inserting the distal ends into
the groove of the heat conducting part.
13. The fabrication method according to claim 8, wherein the
mounting step (d) comprises using the hole of the frame as a guide
hole.
14. The fabrication method according to claim 8, wherein the
housing body formed in the resin injecting step (e) is configured
to expose the chip mounting area and the heat connecting area of
the heat conducting part, a side of the distal end of the
electrical connecting part and a side of the distal end of the
holders adjacent to the heat conducting part.
15. The fabrication method according to claim 8, wherein the holder
separating step (f) forms recesses each extended along bottom
portions of the housing body from the groove of the heat conducting
part to a side of the housing body.
16. A fabrication method of light emitting diode housings,
comprising steps of: (a) preparing a plurality of heat conducting
parts each having a chip mounting area, a heat connecting area
opposed to the chip mounting area and a groove formed adjacent to
the heat connecting area; (b) machining a sheet metal to prepare a
frame array sheet each having an outer periphery, at least one
electrical connecting part and a plurality of holders extended from
the outer periphery to the center of the frame and a hole formed in
the outer periphery; (c) inserting distal ends of the holders into
the groove and placing a distal end of the electrical connecting
part having the wiring area adjacent to the chip mounting area of
the heat conducting part to assemble the heat conducting part to
the frame; (d) mounting a resultant structure of the heat
conducting parts and the frame array sheet to molds; (e) injecting
resin into the mold to form a plurality of housing bodies each
integrally holding the heat conducting part, the electrical
connecting part and the holders, with a portion of the electrical
connecting part and the holders being exposed in part, while
isolating the heat conducting part from the electrical connecting
part; and (f) cutting the electrical connecting parts from the
frame array sheet and separating the holders from the heat
conducting parts.
17. The fabrication method according to claim 16, wherein the
machining step (b) comprises punching.
18. The fabrication method according to claim 16, wherein the
machining step (b) comprises bending the electrical connecting
parts.
19. The fabrication method according to claim 16, wherein the
machining step (b) comprises bending the holders, the method
further comprising a step of: (g) bending the electrical connecting
parts after the cutting step (f).
20. The fabrication method according to claim 16, wherein the
inserting step (c) comprises arranging the distal ends of the
holders opposite to each other and inserting the distal ends into
the grooves of the heat conducting parts.
21. The fabrication method according to claim 16, wherein the
mounting step (d) comprises using the hole of the frame array sheet
as a guide hole.
22. The fabrication method according to claim 16, wherein each of
the housing bodies formed in the resin injecting step (e) is
configured to expose the chip mounting area and the heat connecting
area of the heat conducting part, a side of the distal end of the
electrical connecting part and a side of the distal end of the
holders adjacent to the heat conducting part.
23. The fabrication method according to claim 16, wherein the
holder separating step (f) forms recesses each extended along
bottom portions of the housing body from the groove of the heat
conducting part to a side of the housing body.
Description
CLAIM OF PRIORITY
[0001] This application claims the benefit of Korean Patent
Application No. 2005-13248, filed Feb. 17, 2005 in the Korean
Intellectual Property Office, the disclosure of which is
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a Light Emitting Diode
(LED) housing, and more particularly, an LED housing having a
simple assembly structure, which enables mass production in an easy
fashion, and a fabrication method thereof.
[0004] 2. Description of the Related Art
[0005] A Light Emitting Diode (LED) is a semiconductor device that
is activated in response to electric current to generate various
colors of light. The color of light generated by the LED is mainly
determined by chemical components of LED semiconductor. Such LEDs
have several merits such as longer lifetime, lower driving voltage,
better initial activation characteristics, higher vibration
resistance and higher tolerance on repetitive power switching over
conventional lighting devices using filaments, and thus demand for
them is gradually on the rise.
[0006] In particular, some LEDs such as high power LEDs are
recently adopted in illumination systems and backlight units for
large-sized Liquid Crystal Displays (LCDs). Such high power LEDs
are required to have superior thermal radiation performance because
these systems or units require larger power.
[0007] FIGS. 1 and 2 illustrate a typical high power LED package,
in which FIG. 1 is a perspective cross-sectional view of the high
power LED, and FIG. 2 is a cross-sectional view of the high power
LED mounted on a circuit board.
[0008] Referring to FIG. 1 first, an LED package 10 includes a
thermal connecting member 14 (so-called heat slug) with an LED chip
12 seated thereon. The thermal connecting member 14 also functions
as heat guide means. The LED chip 12 is powered from an external
power source (not shown) via a pair of wires 16 and a pair of leads
18. An encapsulant 20 encapsulates the top portion of the thermal
connecting member 14 including the LED chip 12, and a lens 22 is
capped on the encapsulant 20. A housing 24 is formed typically by
molding, surrounding the thermal connecting member 14 to support
the thermal connecting member 14 and the leads 18.
[0009] The LED package 10 shown in FIG. 1 is mounted on a mother
board 30 as a heat sink as shown in FIG. 2 to constitute an LED
assembly 40. A heat conductive pad 36 such as solder is interposed
between the heat conducting member 14 of the LED package 10 and a
metal body 32 of the main board 30 to promote heat conduction
between them. In addition, the leads 18 are also stably connected
to a circuit pattern 34 of the main board 30.
[0010] The LED package 10 and its mounting structure on the main
board 30 as shown in FIG. 1 are focused to thermal radiation to
efficiently radiate heat to the outside. That is, the LED package
10 is so designed that the thermal connecting member 14 as a heat
sink is mounted directly or via the thermal conductive pad 36 on
the main board 30 in order to radiate heat absorbed from the LED
chip 12 to the outside. Then, a major quantity of heat from the LED
chip 12 is conducted through the thermal connecting member 14 to
the main board 30 and only a minor quantity of heat is radiated to
the air through the surface of the LED package 12 including the
housing 24 and the lens 22.
[0011] However, this structure is disadvantageously complicated to
obstruct the automation of LED package fabrication as well as
require a large number of components to be assembled together,
thereby burdening manufacture cost.
SUMMARY OF THE INVENTION
[0012] The present invention has been made to solve the foregoing
problems of the prior art and it is therefore an object of the
present invention to provide an LED housing and its fabrication
method which can overcome restricted application problems by
isolating electrical connecting parts from a heat conducting
part.
[0013] It is another object of the invention to provide an LED
housing, which can be fabricated from a frame having electrical
connecting parts and a holder for a heat conducting part in order
to simplify process and enhance efficiency, and a fabrication
method thereof.
[0014] In order to realize the above objects, the invention
provides an LED housing comprising: a heat conducting part having a
chip mounting area to be mounted with an LED chip, a heat
connecting area opposed to the chip mounting area and a groove
formed adjacent to the heat connecting area; an electrical
connecting part having a wiring area placed adjacent to the chip
mounting area of the heat conducting part and an external power
connecting area led to the wiring area; and a housing body made of
molding resin, and integrally holding the heat conducting part and
the electrical connecting part while isolating the electrical
connecting part from the heat conducting part, wherein the housing
body is provided with a recess extended from a portion of the
groove of the heat conducting part to a side of the housing
body.
[0015] Preferably, the electrical connecting part may comprise a
pair of lead to be connected with the LED chip by wires,
respectively.
[0016] Preferably, the heat conducting part is electrically
connected to the LED chip.
[0017] Preferably, the chip mounting area has at outer peripheral
portion extended in a light emitting direction forming into a
reflector.
[0018] Preferably, the housing body is configured to expose the
chip mounting area and the heat connecting area of the heat
conducting part and the wiring area of the electrical connecting
part, in which the housing body has a peripheral portion formed
around and extended beyond the chip mounting area of the heat
conducting part and the wiring area of the electrical connecting
part, thereby forming a recess therein.
[0019] In the LED housing of the invention, the heat conducting
part may further comprise a neck formed along an outer peripheral
portion between the chip mounting area and the groove.
[0020] The invention also provides a fabrication method of an LED
housing, comprising steps of: [0021] (a) preparing a heat
conducting part having a chip mounting area, a heat connecting area
opposed to the chip mounting area and a groove formed adjacent to
the heat connecting area; [0022] (b) machining a sheet metal to
prepare a frame having an outer periphery, at least one electrical
connecting part and a plurality of holders extended from the outer
periphery to the center of the frame and a hole formed in the outer
periphery; [0023] (c) inserting distal ends of the holders into the
groove and placing a distal end of the electrical connecting part
having the wiring area adjacent to the chip mounting area of the
heat conducting part to assemble the heat conducting part to the
frame; [0024] (d) mounting a resultant structure of the heat
conducting part and the frame to a mold; [0025] (e) injecting resin
into the mold to form a housing body integrally holding the heat
conducting part, the electrical connecting part and the holders,
with a portion of the electrical connecting part and the holders
being exposed in part, while isolating the heat conducting part
from the electrical connecting part; and [0026] (f) cutting the
electrical connecting part from the frame and separating the
holders from the heat conducting part.
[0027] Furthermore, the invention provides a fabrication method of
LED housings, comprising steps of: [0028] (a) preparing a plurality
of heat conducting parts each having a chip mounting area, a heat
connecting area opposed to the chip mounting area and a groove
formed adjacent to the heat connecting area; [0029] (b) machining a
sheet metal to prepare a frame array sheet each having an outer
periphery, at least one electrical connecting part and a plurality
of holders extended from the outer periphery to the center of the
frame and a hole formed in the outer periphery; [0030] (c)
inserting distal ends of the holders into the groove and placing a
distal end of the electrical connecting part having the wiring area
adjacent to the chip mounting area of the heat conducting part to
assemble the heat conducting part to the frame; [0031] (d) mounting
a resultant structure of the heat conducting parts and the frame
sheet array to a mold; [0032] (e) injecting resin into the mold to
form a plurality of housing bodies each integrally holding the heat
conducting part, the electrical connecting part and the holders,
with a portion of the electrical connecting part and the holders
being exposed in part, while isolating the heat conducting part
from the electrical connecting part; and [0033] (f) cutting the
electrical connecting parts from the frame array sheet and
separating the holders from the heat conducting parts.
[0034] In the above fabrication methods, the machining step (b) may
comprise punching, wherein the electrical connecting part may be
bent.
[0035] In the above fabrication methods, the machining step (b)
comprises bending the holders, and the method further comprising a
step of: (g) bending the electrical connecting part after the
cutting step (f).
[0036] Preferably, the inserting step (c) may comprise arranging
the distal ends of the holders opposite to each other and inserting
the distal ends into the groove of the heat conducting part.
[0037] In the above fabrication methods, the mounting step (d) may
comprise using the hole of the frame as a guide hole.
[0038] Preferably, the housing body formed in the resin injecting
step (e) is configured to expose the chip mounting area and the
heat connecting area of the heat conducting part, a side of the
distal end of the electrical connecting part and a side of the
distal end of the holders adjacent to the heat conducting part.
[0039] In the above fabrication methods, the holder separating step
(f) may form recesses each extended along bottom portions of the
housing body from the groove of the heat conducting part to a side
of the housing body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] The above and other objects, features and other advantages
of the present invention will be more clearly understood from the
following detailed description taken in conjunction with the
accompanying drawings, in which:
[0041] FIG. 1 is a sectional perspective view illustrating a
conventional high power LED package;
[0042] FIG. 2 is a sectional view illustrating the LED package
shown in FIG. 1, mounted on a board;
[0043] FIG. 3 is a perspective view illustrating a first embodiment
of the LED housing according to the invention;
[0044] FIG. 4 is a plan view of the LED housing shown in FIG.
3;
[0045] FIG. 5 is a cross-sectional view taken along line V-V in
FIG. 4;
[0046] FIG. 6 is a cross-sectional view taken along line VI-VI in
FIG. 4;
[0047] FIG. 7 is a bottom perspective view of the LED housing shown
in FIG. 3;
[0048] FIG. 8 is a perspective view illustrating an LED housing as
shown in FIG. 3, capped with a cover;
[0049] FIG. 9 is a cross-sectional view of the LED housing shown in
FIG. 8;
[0050] FIG. 10 is a cross-sectional view of a second embodiment of
the LED housing according to the invention, shown in cross-section
corresponding to FIG. 5;
[0051] FIG. 11 is a cross-sectional view of a third embodiment of
the LED housing according to the invention, shown in cross-section
corresponding to FIG. 5;
[0052] FIG. 12 is a cross-sectional view of a fourth embodiment of
the LED housing according to the invention, shown in cross-section
corresponding to FIG. 5;
[0053] FIG. 13 is a perspective view illustrating an LED housing as
shown in FIG. 12, capped with a cover;
[0054] FIGS. 14 to 22 are views illustrating a fabrication process
of an LED housing according to the invention in a stepwise manner;
and
[0055] FIG. 23 is a plan view illustrating a fabrication process of
LED housings by using a frame array sheet according to the
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0056] Preferred embodiments of the present invention will now be
described in detail with reference to the accompanying
drawings.
[0057] Referring to FIGS. 3 to 7 first, an LED housing 100 of the
invention includes a heat conducting part 110, a pair of electrical
connecting parts 120 and a housing body 130.
[0058] The heat conducting part 110 is preferably made of a metal
piece having high heat conductivity. The heat conducting part 110
has a chip mounting area 112 mounted with an LED chip 102, a heat
connecting area 114 opposed to the chip mounting area 112, a groove
118 formed adjacent to the heat connecting area 114 and a neck 116
which is a reduced width portion between the groove 118 and the
chip mounting area 112.
[0059] Each of the electrical connecting parts 120 is made of a
strip-shaped lead in use for electrical connection, and has a
wiring area 120a placed adjacent to the chip mounting area 112 of
the heat conducting part 110 and an external power connecting area
120b connected to the wire connecting area 120a.
[0060] The LED chip 102 is fixed to the chip mounting area 112 by
for example adhesive and to the wiring areas 120a of the electrical
connecting parts 110 by wires 104.
[0061] The housing body 130 is made of molding compound, and formed
integrally around the heat conducting part 110 and the electrical
connecting parts 120. The housing body 130 isolates the heat
conducting part 110 from the electrical connecting parts 120. In
addition, a circular opening 132 is provided to expose the chip
mounting area 112 of the heat conducting part 110 and the wiring
areas 120a of the electrical connecting parts 120.
[0062] The housing body 130 partially fills the groove 118 of the
heat conducting part 110, and has recesses 134 extended from the
groove 118 to sides of the housing body 130 to expose portions of
the groove 118. The recesses 134 can receive solders during
following process of soldering the LED housing 100 to a board,
thereby enhancing the coupling force between the LED housing 100
and the board.
[0063] Referring to FIGS. 8 and 9, a transparent cover 140 is
capped on the LED housing 100 of the invention to provide an LED
package. The cover 140 is made by injection molding of for example
transparent plastic, and has a reflecting surface 142 for
reflecting light generated by the LED chip 102, an upper radiating
surface 144 for radiating reflected light to the outside and a
lower radiating surface 146 for radiating light directly incident
from the LED chip 102 to the outside. The cover 140 is shaped
symmetrically about the axis A or rotationally symmetric.
[0064] A transparent encapsulant 150 preferably made of elastic
resin is provided between the cover 140 and the LED housing 100.
The elastic resin may include gel type substance such as silicone
which has not only excellent optical characteristic due to large
refractive index but also excellent resistance against yellowing,
that is, change in quality caused by single wavelength light.
Furthermore, silicone maintains jell or elastomer state even after
hardening, and thus can stably protect the LED chip 102 from
stress, vibrations and external impact.
[0065] Of course, the shape of the cover 140 is illustrative only,
but various types of lenses and covers can be used instead. For
example, the dome-shaped lens 22 as shown in FIG. 1 can be used.
Furthermore, the transparent encapsulant 150 made of elastic
material can be optionally omitted.
[0066] FIG. 10 shows a second embodiment of the LED housing
according to the invention. Examining the LED housing 200 of this
embodiment, an LED chip 202 is electrically connected to the
electrical connecting part 220 and the heat conducting part 110 by
wires 204, respectively. Therefore, the heat conducting part 110
itself functions as an electrical connecting part. Then, a lead 222
designated with dotted line can be omitted. Other construction of
the LED housing 200 of this embodiment is substantially the same as
that of the LED housing 100 of the first embodiment. The same or
similar components are designated with the same reference signs in
the 200s and their description will be omitted.
[0067] FIG. 11 shows a third embodiment of the LED housing
according to the invention. Examining the LED housing 300 of this
embodiment, in a heat conducting part 310, a chip mounting area 312
is protruded at the outer circumference upward to surround an LED
chip 302, thereby forming a reflector 312a. The inside of the
reflector 312a is shaped as a concave mirror in order to reflect
light generated by the LED chip 302 in upward direction. Other
construction of the LED housing 300 of this embodiment is
substantially the same as that of the above-described LED housing
100. The same or similar components are designated with the same
reference signs by the 300s, and their description will be
omitted.
[0068] FIG. 12 shows a fourth embodiment of the LED housing
according to the invention. Examining the LED housing 400 of this
embodiment, a housing body 400 is extended by its outer
circumference beyond a chip mounting area 412 of a heat conducting
part 410 and an LED chip 402 to form a cavity 432 around them. The
housing body 400 has an inside slope formed around the cavity 432
and a curved outside surface 436.
[0069] Optionally, the housing body 400 may be made of high
reflectivity polymer. In this fashion, it is possible to reflect
light generated by the LED chip 402 in upward direction by using
the slope 434 as a reflecting surface.
[0070] For a polymer of a high reflectivity, NM114WA and NM04WA,
which are product names of Otsuka Chemical Co., Ltd. can be used.
Specifically, NM114WA has an initial reflectivity of 88.3% and
maintains a reflectivity of 78.0% after two hours for a wavelength
of 470 nm. NM04WA has an initial reflectivity of 89.0% and
maintains a reflectivity of 89.0% after two hours for a wavelength
of 470 nm. For an excellent reflectivity molding material, those
containing TiO.sub.2 are known in the art.
[0071] Alternatively, the housing body 400 can be made of metal or
polymer of a low reflectivity and high reflectivity material can be
provided in the form of a film on the slope 434. This film can be
realized using metal of a high reflectivity or the above-described
polymer of a high reflectivity.
[0072] FIG. 13 illustrates an LED package embodied by capping a
transparent cover 440 on an LED housing 400 as shown in FIG.
12.
[0073] In detail, transparent encapsulant 450 made of transparent
resin is provided within a cavity 432 of an LED housing 400, and a
transparent cover 440 is coupled to the top of the LED housing 400.
The transparent encapsulant 450 may be made of epoxy resin, and
preferably afore-described elastic resin.
[0074] The transparent cover 440 has a reflecting surface 442 and a
radiating surface 444 for radiating reflected light to the outside.
The cover 440 is shaped symmetrically about the axis A and
rotationally symmetric.
[0075] The housing body 400 may be made from transparent resin.
Then, a curved surface 436 of the housing body 400 functions as a
lower radiating surface that radiates light from the LED chip 402
in lateral direction. The light radiation pattern obtained from the
LED package is substantially the same as that described above with
reference to FIGS. 8 and 9.
[0076] Following description will now present a fabrication process
of the LED housing 100 of the invention with reference to FIGS. 14
to 22.
[0077] Preparing Heat Conducting Part and Frame
[0078] A heat conducting part 110 as described with reference to
FIGS. 3 to 7 is prepared from a metal piece and a frame 128 as
shown in FIGS. 14, 14a and 14b are prepared from a sheet metal or
metal plate preferably by pressing or punching. The frame 128 has a
pair of electrical connecting parts 120 and a pair of holders 124
which are extended from an outer circumference 126 to the center.
Open areas are formed between the electrical connecting parts 120,
the holders 124 and the outer circumference 126.
[0079] As shown in FIG. 14a, each electrical connecting part 120 is
bent and extended from the frame 128. An external power connecting
area 120b is provided at a first end adjacent to the frame 128, and
a wire connecting area 120a is provided at a second end opposed to
the first end. Alternatively, the electrical connecting part 120
may be extended plat from the frame 128 as designated with dot line
in FIG. 16.
[0080] A proximal end 124b of each holder 124 is extended flat from
the frame 128, and a distal end 124a opposed to the proximal end
124b is inserted into the groove 118 of the heat conducting part
110, acting as a holder for maintaining the heat conducting part
110 in position. The distal end 124a of the holder is shaped
matching the recess 118 of the electrical connecting part 110.
Alternatively, the holder 124 may be bent and extended from the
frame 128, as designated with dot line in FIG. 17.
[0081] Besides, holes H are perforated in corners of the frame 128
to locate the frame 128 and maintain its position. Of course, the
holes H serve to receive guide pins of a hold (not shown) when the
frame 140 is mounted to the mold in following process.
[0082] Assembling Heat Conducting Part to Frame
[0083] Then, as shown in FIGS. 15 to 17, the heat conducting part
110 is mounted or assembled to the frame 128. To be specific, the
distal ends 124a of the holders 124 are inserted into the groove of
the heat conducting part and the wiring areas 120a of the
electrical connecting part 120 are placed adjacent to the chip
mounting areas 112 of the heat conducting part 110, in which the
electrical connecting parts 120 maintain a predetermined space from
the heat conducting part 110. This makes the holders 120 securely
hold the heat conducting part 110 so that the heat conducting part
can maintain its position following process of mold mounting and
resin injection.
[0084] Mold Mounting and Resin Injection
[0085] Next the frame 140 assembled with the heat conducting part
110 is mounted to a mold (not shown) by inserting guide pins of
mold into the holes H of the frame 128. Then, molding resin is
injected into the mold to integrally mold the heat conducting part
110 and parts of the frame 128 adjacent to the heat conducting part
110, thereby forming a housing body 130 having an opening 132 that
exposes the chip mounting area 112 of the heat conducting part 110
and the wiring area 120a of the electrical connecting part 120.
[0086] Describing in more detail, the housing body 130 integrally
holds portions of the electrical connecting parts 120 adjacent to
the wiring areas 120a and portions of the holders 124 adjacent to
the distal ends 124a. Then, the heat conducting part 110 is held or
encapsulated by the housing body 130 except for the chip mounting
area 112 and the heat connecting area 114. Besides, the wiring
areas 120a of the electrical connecting parts 120 are exposed to
the outside, and the external power connecting parts 120b of the
electrical connecting parts 120 are projected out of the housing
body 130.
[0087] Electrical Connecting Part Cutting and Holder Separation
[0088] As shown in FIG. 22, the external power connecting areas
120a of the electrical connecting parts 120 are cut along cutting
lines Lc from the frame 128, and the holders 124 are withdrawn out
of the groove 118 of the heat conducting part 110. Withdrawing the
holders 124 leaves recesses 134 (see FIG. 6) in the housing body
130, which in turn act to receive solders in following process of
soldering the LED housing 100 to a board (e.g., metal PCB), thereby
enforcing the bonding force between the LED housing 100 and the
board.
[0089] If the electrically connecting parts 120 are flat as shown
in dot line, they are bent into the configuration designated with
solid line.
[0090] Then, an LED chip 102 is attached to the chip mounting area
112 by for example adhesive, and electrically connected to the
electrical connecting parts 120 by wires 104.
[0091] Mounting Transparent Cover
[0092] The LED housing 100 shown in FIG. 22 can be capped with a
transparent cover 140 as shown in FIGS. 8 and 9. In this case, the
cover 140 is turned upside down, transparent encapsulant 150 of for
example silicone is filled into a hollow space of the cover 140,
and then the LED housing 100 is turned upside down and placed on
the cover 140 with the LED chip 102 facing downward. As the
transparent encapsulant 140 is cured from this state, the LED
package as shown in FIGS. 8 and 9 can be produced.
[0093] Process on Frame Array Sheet
[0094] FIG. 23 shows a frame array sheet 160 having a plurality of
frame areas 128' arrayed therein. Each frame area 128' is shaped
substantially the same as the afore-described frame 128.
[0095] Therefore, the frame array sheet 160 can be used to produce
a number of LED housing bodies 130 in the plurality of frame areas
128' according to the same process as described above, in which
holes H formed in the periphery of the frame array sheet 160 are
used as guide holes or locating holes.
[0096] After forming the LED housings 100 according to the above
process, the frame array sheet 160 is cut along cutting lines Lc
and the holders 124 are withdrawn out of the housing bodies 130 and
the recesses of the heat conducting parts 110, so as to accomplish
a plurality of LED housings 100.
[0097] In this fashion, the above process allows the plurality of
LED housings 100 to be automatically produced by using one frame
array sheet 160.
[0098] The afore-described process fabrication of an LED housing
and an LED package having the same LED housing can be applied
equally to fabrication of the LED housing 100 of the first
embodiment as well as the LED housings 200 and 300 of the second
and third embodiments.
[0099] In case of the fourth embodiment, this fabrication process
is equally applied to fabrication of the LED housing 400, but
differs in coupling the cover 440 to the LED housing 400. In the
LED housing 400 of the fourth embodiment, transparent encapsulant
450 is filled into the cavity C beforehand as illustrated in FIG.
13, followed by bonding the transparent cover 440 onto the top of
the encapsulant 450.
[0100] As described above, the LED housing and its fabrication
method of the present invention can overcome restricted application
problems by isolating the electrical connecting part(s) from the
heat conducting part. Furthermore, it is possible to simplify
process and enhance efficiency by fabricating the LED housing from
a frame having the electrical connecting part(s) and a holder for
the heat conducting part.
[0101] While the present invention has been shown and described in
connection with the preferred embodiments, it will be apparent to
those skilled in the art that modifications and variations can be
made without departing from the spirit and scope of the invention
as defined by the appended claims.
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