LIGHT EMITTING DIODE PACKAGE

Abstract

A light emitting diode (LED) package includes an LED chip, a first lead frame and a second lead frame electrically connected to the LED chip and separated by a space, and a housing disposed on the first lead frame and the second lead frame. The housing includes an external housing surrounding a cavity, the cavity exposing a first portion of the first lead frame and a first portion of the second lead frame, and an internal housing disposed in the space, the internal housing covering a top portion of the first lead frame and a top portion of the second lead frame.

Claims

1. A light emitting diode (LED) package, comprising: a first lead frame and a second lead frame spaced apart from each other, the first lead frame and the second lead frame respectively comprising a first side and second side facing each other; at least one LED chip disposed on the first lead frame; a wire electrically connecting the LED chip and the second lead frame; and a housing disposed on the first lead frame and the second lead frame; wherein the first lead frame comprises a first protrusion in the first side and the second lead frame comprises a corresponding recess in the second side to increase a mechanical bonding strength with a housing, wherein at least one portion of the LED chip is disposed within the first protrusion.

2. The LED package of claim 1, wherein the first protrusion is disposed in the middle of the first side.

3. The LED package of claim 1, wherein the corresponding recess is disposed in the middle of the second side.

4. The LED package of claim 3, wherein the second lead frame comprises a second protrusion disposed at a peripheral of the corresponding recess, and wherein the wire is bonded to the second protrusion of the second lead frame.

5. The LED package of claim 1, wherein the first protrusion has a width wider than that of the LED chip.

6. The LED package of claim 1, further comprising a zener diode disposed in the second lead frame.

7. The LED package of claim 4, further comprising a zener diode disposed on the second protrusion.

8. The LED package of claim 1, wherein the first protrusion and the corresponding recess comprise an uplift portion, respectively.

9. The LED package of claim 1, wherein each of the first lead frame and the second frame comprises a side portion and a bottom portion exposed from the housing.

10. The LED package of claim 9, wherein the bottom portion is coplanar and flush with a bottom surface of the housing.

11. The LED package of claim 1, wherein the first protrusion is substantially rectangular and the corresponding recess is substantially rectangular.

12. A light emitting diode (LED) package, comprising: a first lead frame and a second lead frame spaced apart from each other by a space, the first lead frame and the second lead frame respectively comprising a first side and a second side facing each other; at least one LED chip disposed on the first lead frame; a housing disposed on the first lead frame and the second lead frame; wherein the space comprises a crooked shape, wherein the first lead frame comprises a first protrusion in the first side forming a lengthened side surface of the first side of the first lead frame to increase a mechanical bonding strength with the housing.

13. The LED package of claim 12, wherein the second lead frame comprises a corresponding first recess in the second side forming a lengthened side surface of the second side of the second lead frame to increase a mechanical bonding strength with the housing.

14. The LED package of claim 13, wherein the first recess is disposed in a middle of the second side.

15. The LED package of claim 12, wherein the first protrusion in disposed in a middle of the first side.

16. The LED package of claim 12, wherein the first protrusion is disposed between a pair of second recesses disposed in the first side.

17. The LED package of claim 12, wherein the first protrusion has a width wider than that of the LED chip.

18. The LED package of claim 12, wherein each of the first lead frame and the second frame comprises a side portion and a bottom portion exposed from the housing.

19. The LED package of claim 18, wherein the bottom portion is coplanar and flush with a bottom surface of the housing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the description serve to explain the principles of the invention.

[0019] FIGS. 1(a), 1(b), 1(c), 2(a), 2(b), and 2(c) illustrate conventional LED packages.

[0020] FIGS. 3(a), 3(b), and 3(c) illustrate an LED package according to an exemplary embodiment of the invention.

[0021] FIG. 4 is an enlarged cross-sectional view of circle A shown in FIG. 3(b).

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

[0022] The invention is described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure is thorough and will fully convey the scope of the invention to those skilled in the art. In the drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. Like reference numerals in the drawings denote like elements.

[0023] It will be understood that when an element such as a layer, film, region or substrate is referred to as being on another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being directly on another element, no intervening elements are present.

[0024] FIGS. 3(a) to 3(c) illustrate an LED package according to an exemplary embodiment of the invention, and FIG. 4 is an enlarged cross-sectional view of circle A shown in FIG. 3(b).

[0025] According to the present exemplary embodiment, an LED package 3 includes lead frames 31, 32, as shown in FIG. 3(a).

[0026] Referring to FIG. 3(a), the lead frames 31, 32 are separated from each other. The lead frames 31, 32 include uplift portions 31a, 32a respectively formed at adjacent portions thereof. The uplift portions 31a, 32a may be formed by stamping a substantially flat metal plate using, for example, a punch, such that portions of the metal plate respectively corresponding to an anode and a cathode are raised relatively higher than the rest of the lead frames 31 and 32.

[0027] Further, the lead frames 31, 32 are disposed to face each other. More specifically, a substantially rectangular tab portion of the uplift portion 31a of the first lead frame 31 is disposed in a corresponding substantially rectangular recessed area in the uplift portion 32a of the second lead frame 32 to lengthen a space formed therebetween, as illustrated in FIG. 3(a).

[0028] Referring to FIG. 3(b), the LED package 3 according to the present exemplary embodiment includes a housing which supports the first and second lead frames 31, 32 while surrounding the uplift portions 31a, 32a. The housing may be divided into an external housing 33 and an internal housing 37.

[0029] The external housing 33 is open at an upper side thereof and includes a cavity 331 for receiving an LED chip 34.

[0030] Further, the external housing 33 may be formed thereon with a mounting hole 36 in consideration of mounting a lens part (not shown). The cavity 331 may be provided therein with an encapsulation material (not shown) which entirely encapsulates the internal housing 37. The encapsulation material may be formed of a light-transmitting resin, for example, silicone resin or epoxy resin.

[0031] The internal housing 37 is integrally formed with the external housing 33 by injection molding and has a lower height than the external housing 33. The internal housing 37 and the external housing 33 are configured to expose some of upper surfaces 311, 321 of the first and second lead frames 31, 32. In the present exemplary embodiment, the internal housing 37 is disposed inside the cavity 331 and the external housing 33 is disposed outside the cavity 331, to be connected to the internal housing 37. The external housing 33 and the internal housing 37 may be formed of, for example, PPA or epoxy.

[0032] The internal housing 37 includes a reinforcing portion 371, bridges 372, 373, and exposing portions 374, 375, and has a substantially cross shape.

[0033] The reinforcing portion 371 fills a space between the first and second lead frames 31, 32, including the lengthened space formed by the substantially rectangular tab and recess portions. In particular, as shown in FIG. 4, the reinforcing portion 371 surrounds the uplift portions 31a, 32a of the first and second lead frames 31, 32, and may be formed higher than the uplift portions 31a, 32a. Since the structure of the reinforcing portion 371 completely surrounds the uplift portions 31a, 32a and the reinforcing portion 371 is formed higher than the uplift portions 31a, 32a, physical strength at a portion dividing the first and second lead frames 31, 32 may be further enhanced and moisture absorption may be prevented.

[0034] The bridges 372, 373 extend from the reinforcing portion 371 and are connected to the external housing 33. In the present exemplary embodiment, a first bridge 372 extends from the reinforcing portion 371 to be disposed on a partial region of the first lead frame 31 and is connected to the external housing 33, and a second bridge 373 extends from the reinforcing portion 371 to be disposed on a partial region of the second lead frame 32 and is connected to the external housing 33.

[0035] The exposing portions 374, 375 partially expose upper surfaces 311, 321 of the first and second lead frames 31, 32. In the present exemplary embodiment, the first exposing portion 374 exposes a portion of the upper surface 311 of the first lead frame 31 within the first bridge 372 to provide a mounting area for the LED chip 34. The LED chip 34 is mounted on the portion of the upper surface 311 of the first lead frame 31 exposed by the first exposing portion 374. The mounted LED chip 34 is connected to one of exposed portions of the upper surface 321 of the second lead frame 32 via a first bonding wire W1, with the second bridge 373 interposed between the exposed portions of the upper surface 321.

[0036] Although the first exposing portion 374 is illustrated as having a rectangle shape with rounded corners in the present exemplary embodiment, the first exposing portion 374 may alternatively have any shape in consideration of the shape and size of the LED chip 34 so long as the LED chip 34 can be mounted at the center of the first exposing portion 374. Further, in addition to the first exposing portion 374, other portions of the upper surface 311 of the first lead frame 31 may be exposed with the first bridge 372 interposed therebetween, and may be used as a mounting area or a bonding area.

[0037] The first exposing portion 374 may have an inclined inner wall to reflect light emitted from the LED chip 34. Further, the first exposing portion 374 is provided with an internal encapsulation material (not shown) which covers the LED chip 34 and may be formed of a light-transmitting resin containing at least one phosphor.

[0038] The internal housing 37 is formed therein with the second exposing portion 375 through the reinforcing portion 371 and the second bridge 373 to provide a bonding area.

[0039] A Zener diode ZD may be mounted on the other exposed portion of the upper surface 321 of the second lead frame 32, with the second bridge 373 interposed between the exposed portions of the upper surface 321, and a second bonding wire W2 for electrically connecting the Zener diode ZD to the first lead frame 31 is bonded to the bonding area provided by the second exposing portion 375. The Zener diode ZD is to protect the LED chip 34 from electrostatic discharge.

[0040] The second exposing portion 375 allows the Zener diode ZD to be electrically connected to the first and second lead frames 31, 32 via the second boding wire W2 without crossing the first bonding wire W1.

[0041] Referring to FIG. 3(c), a bottom surface 330 of the LED package 3 includes bottom surfaces of the external housing 33 and the internal housing 37, and is parallel with lower surfaces 312, 322 of the first and second lead frames 31, 32 excluding the uplift portions 31a, 32a. The bottom surface 330 of the LED package 3 may be coplanar and flush with lower surfaces 312, 322 of the first and second lead frames 31, 32. Accordingly, heat from the LED chip 34 may be discharged through the lower surfaces 312, 322 of the first and second lead frames 31, 32, thereby improving heat dissipation efficiency from the LED package.

[0042] According to the exemplary embodiments of the present invention, the LED package includes a housing configured to surround uplift portions formed on lead frames electrically connected to an LED chip. The LED package is to increase a heat dissipation area while increasing physical strength between the lead frames and preventing moisture absorption. Particularly, a reinforcing portion filling a space between the lead frames may increase physical strength between the lead frames.

[0043] Although the invention has been illustrated with reference to some exemplary embodiments in conjunction with the drawings, it will be apparent to those skilled in the art that various modifications and changes can be made to the invention without departing from the spirit and scope of the invention. Further, it should be understood that some features of a certain embodiment may also be applied to other embodiment without departing from the spirit and scope of the invention. Therefore, it should be understood that the embodiments are provided by way of illustration only and are given to provide complete disclosure of the invention and to provide thorough understanding of the invention to those skilled in the art. Thus, it is intended that the invention cover the modifications and variations provided they fall within the scope of the appended claims and their equivalents.