Source: https://patents.justia.com/patent/8735931
Timestamp: 2019-07-17 08:40:37
Document Index: 175729651

Matched Legal Cases: ['Application No. 2006', 'art 110', 'art 120', 'art 110', 'art 120', 'art 110', 'art 120', 'art 110', 'art 110', 'art 120', 'art 110', 'art 120', 'art 110', 'Application No. 2007', 'Application No. 2007', 'Application No. 200710096913', 'Application No. 2007', 'Application No. 2010']

US Patent for Light emitting diode package and fabrication method thereof Patent (Patent # 8,735,931 issued May 27, 2014) - Justia Patents Search
Justia Patents With Housing Or Contact StructureUS Patent for Light emitting diode package and fabrication method thereof Patent (Patent # 8,735,931)
Light emitting diode package and fabrication method thereof
Oct 19, 2010 - Samsung Electronics
An LED package and a fabrication method therefor. The LED package includes first and second lead frames made of heat and electric conductors, each of the lead frames comprising a planar base and extensions extending in opposed directions and upward directions from the base. The package also includes a package body made of a resin and configured to surround the extensions of the first and second lead frames to fix the first and second lead frames while exposing underside surfaces of the first and second lead frames. The LED package further includes a light emitting diode chip disposed on an upper surface of the base of the first lead frame and electrically connected to the bases of the first and second lead frames, and a transparent encapsulant for encapsulating the light emitting diode chip.
This application is a Divisional of U.S. patent application Ser. No. 11/730,965, filed on Apr. 5, 2007, and claims the benefit of Korean Patent Application No. 2006-0034706 filed on Apr. 17, 2006, in the Korean Intellectual Property Office, the entire contents of each of which are hereby incorporated herein by reference.
Alight emitting diode (LED) is a semiconductor device for generating various colors of light in response to current application. The colors generated from the LED are determined by the chemical substances constituting the semiconductor of the LED. Such an LED has various merits such as a long lifetime, low power, excellent initial driving characteristics, high resistance for vibration and high tolerance for frequent power on/off compared to a light emitting device based on filament, and thus there has been a steadily increasing demand for the LEDs.
The LED package shown in FIG. 3 is suggested in “SEMICONDUCTOR LIGHT-EMITTING DEVICE,” U.S. Patent Application Publication No. 2005/0057144 (published on May 17, 2005). In this LED device or LED package, a cup-shaped reflecting frame 2 is installed on a surface of the substrate 1 with circuit patterns 3 and 6 formed thereon, and an LED chip 4 is mounted in the cup-shaped portion and electrically connected to the circuit pattern 3. In the meantime, the reference numeral 7 represents phosphor, the reference numeral 8 represents diffuser and the reference numeral 9 represents resin.
The present invention has been made to solve the foregoing problems of the prior art and therefore an aspect of the present invention is to provide an LED package which can achieve superior heat radiation efficiency with a simple configuration.
The configurations of the first and second lead frames 110 and 120 can be more clearly understood with reference to FIG. 16. That is, the first and second lead frames 110 and 120 are obtained by cutting the extensions 114b and 124b of a frame structure 102b in FIG. 16 in a suitable length.
The LED package 100-1 shown in FIG. 12 has the same configuration as FIGS. 10 and 11 except for the feature that the encapsulant 150 in FIGS. 10 and 11 is substituted by an encapsulant 150-1 and a lens 154. The lens 154 can be made of various transparent materials, guiding the light emitted from the LED chip 140 to the outside in a desired beam angle. In FIG. 12, the lens 154 is fabricated separately and then attached to the encapsulant 150-1 and the protrusion 134 by an adhesive layer 152. Alternatively, the lens can be formed on upper surfaces of the encapsulant 150-1 and the protrusion 134 by transfer molding, etc.
First, a metal plate or a sheet metal of a predetermined thickness is prepared and made into a preliminary frame structure 102a shown in FIG. 15 via punching or blanking. The preliminary frame structure 102a includes a peripheral portion 104 and a first lead frame part 110a and a second lead frame part 120a formed in the inner side of the peripheral portion 104. The first lead frame part 110a is to be the first lead frame 110 and the second lead frame part 120a is to be the second lead frame 120 described hereinabove after the frame structure 102a undergoes the following fabrication steps described later.
The first lead frame part 110a is composed of a base 112 of a relatively larger area and a pair of extensions 114a extended from opposed ends of the base 112 to the peripheral portion 104. The second lead frame part 120a is formed at a predetermined interval from the first lead frame part 110a, in the shape of a narrow strip and has opposed ends connected to the peripheral portion 104.
In addition, holes H are formed in the corners of the frame structure 102. The holes H are used to fix or guide the frame structure 102a.
The frame structure 102a shown in FIG. 15 is bent via pressing, etc. to obtain a frame structure 102b shown in FIG. 16.
As a result, the extensions 114b of the first lead frame part 110b are bent in a shape that is identical to the one shown in FIG. 8. The only difference is that the extensions 114b in the step shown in FIG. 16 are still connected to the frame structure 102b whereas the extensions 114 shown in FIG. 8 are independently separated.
In addition, the second lead frame part 120b are bent in such a way that a base 122 is formed in the middle with the extensions 124b formed at opposed ends from the base 122.
Then, as shown in FIG. 17, the frame structure 102b is disposed in a mold M and a resin is injected into the mold M to form a package body 130 as shown in FIG. 18. The shape of the package body 130 is identical to the one shown in FIGS. 4 to 8.
Thereafter, an LED chip 140 is disposed and electrically connected on the base 112 of the first lead frame part 110b inside a recess 132 of the package body 130 while electrically connected to the base 122 of the second lead frame part 120b by a wire 142. The LED chip 140 is illustrated as a vertical structure but it can be a horizontal structure. In this case, the LED chip is electrically connected to the base 112 of the first lead frame part 110b by the wire.
Then, a resin is poured into the recess 132 to form a convex shape and cured to obtain an encapsulant 150 shown in FIG. 9. Then, the extensions 114b and 124b are cut along the cutting line LT to complete an LED package 100. Of course, cutting can be done prior to forming the encapsulant 150.
In addition, the frame structure 102b can be modified to obtain the packages 100-2 and 100-3 shown in FIG. 13 or 14.
For example, as shown in FIG. 20, when preparing the frame structure 102b, the sloping surfaces 123 are formed in a length direction in opposed portions of the bottom surface of the base 122-2. The steps shown in FIGS. 17 to 19 can be implemented on this frame structure 102 to obtain the package 100-2 shown in FIG. 13. In FIG. 20, the opposed sloping surfaces in the underside surface of the base 122-2 are omitted in the drawing for convenience, but the shape of the sloping surfaces is identical to the one shown in FIG. 13.
This frame array sheet 1002 is obtained by punching or blanking a metal plate or a sheet metal of a predetermined thickness. In the frame array sheet 1002, a plurality of frame structure regions 1102 are formed, which correspond to a plurality of the frame structure shown in FIG. 15. Therefore, the frame array sheet 1002 is composed of a plurality of frame structures 102a shown in FIG. 15.
first and second lead frames spaced apart from each other and formed of a heat and electric conductor;
a package body fixing the first and second lead frames while exposing an underside surface of at least one of the first and second lead frames;
a light emitting diode chip disposed on an upper surface of the first lead frame or the second lead frame; and
a transparent encapsulant for encapsulating the light emitting diode chip,
wherein each of the first and second lead frames comprises a planar base and a pair of extensions,
wherein the extensions of the first lead frame extend in opposite directions and an upward direction from opposed ends of the planar base of the first lead frame, and the extensions of the second lead frame extend in opposite directions and an upward direction from opposed ends of the planar base of the second lead frame, and
wherein the planar base and extensions of the first lead frame extend, in a lengthwise direction of the first lead frame, substantially in parallel with those of the second lead frame.
2. The light emitting diode package according to claim 1, wherein the package body has a recess formed around the light emitting diode chip and a protrusion is formed in a predetermined width on an upper end of the recess.
3. The light emitting diode package according to claim 2, wherein a portion of the transparent encapsulant fills the recess and another portion of the transparent encapsulant protrudes over the protrusion in a predetermined curvature.
4. The light emitting diode package according to claim 1, wherein the underside surfaces of the bases of the first and second lead frames are coplanar with an underside surface of the package body.
5. The light emitting diode package according to claim 1, wherein ends of the extensions are positioned at side portions of the package body.
6. The light emitting diode package according to claim 1, wherein at least one of the extensions of the first lead frame extends out of the package body to form a terminal.
7. The light emitting diode package according to claim 1, wherein the second lead frame has a smaller width than the first lead frame.
8. The light emitting diode package according to claim 1, wherein the distal ends of each of the pair of extensions extend to the outside of the package body.
9. The light emitting diode package according to claim 1, wherein the at least one of the first and second lead frames is partially removed from the exposed underside surface thereof or another surface thereof parallel to the exposed underside surface.
10. The light emitting diode package according to claim 1, wherein distal ends of each pair of extensions of the first and second lead frames extend from side portions of the package body.
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Patent number: 8735931
Filed: Oct 19, 2010
Patent Publication Number: 20110031526
Inventors: Kyung Taeg Han (Gyunggi-Do), In Tae Yeo (Seoul), Hun Joo Hahm (Gyunggi-Do), Chang Ho Song (Seoul), Seong Yeon Han (Gwangju), Yoon Sung Na (Gyunggi-Do), Dae Yeon Kim (Gyunggi-Do), Ho Sik Ahn (Incheon), Young Sam Park (Seoul)
Primary Examiner: Cathy N Lam
Application Number: 12/907,348
Current U.S. Class: With Housing Or Contact Structure (257/99); Encapsulated (257/100); Lead Frames Fixed On Or Encapsulated In Insulating Substrates (epo) (257/E23.066); Device Controllable Only By Variation Of Electric Current Supplied Or The Electric Potential Applied To Electrodes Carrying Current To Be Rectified, Amplified, Oscillated, Or Switched, E.g., Two-terminal Device (epo) (257/E21.052); Packaging (e.g., With Mounting, Encapsulating, Etc.) Or Treatment Of Packaged Semiconductor (438/26)