KR20090102208A - Heat radiating type led package - Google Patents

Abstract

PURPOSE: A heat dissipation LED package is provided to prevent the lowering of the performance and the life due to the deterioration of the LED chip regardless of the size of the package by increasing a heat dissipation area. CONSTITUTION: A heat dissipation LED package(1) includes an LED chip(10), a body(20), and a lead frame(40). The body is formed to surround the LED chip. One end of the lead frame is adjacently arranged. The other end of the lead frame is protruded to the outside of the body. A groove part(421,441) is formed in the lead frame arranged in the bottom surface to increase a heat dissipation area.

Description

Heat dissipation LED package {HEAT RADIATING TYPE LED PACKAGE}

The present invention relates to a heat dissipation LED package, and more particularly, to a heat dissipation LED package that can widen the heat dissipation area by forming a groove in a lead frame disposed on the bottom surface of the body, so that heat dissipation can be smoothly performed. will be.

In general, a light emitting diode (LED) is a device in which electrons and holes meet and emit light in a P-N semiconductor junction by application of current, and are generally manufactured in a package structure in which an LED chip is mounted. Such LED packages are generally mounted on a printed circuit board (PCB) and configured to emit light by receiving a current from an electrode formed on the printed circuit board.

In the LED package, heat generated from the LED chip directly affects the light emitting performance and lifetime of the LED package. The reason is that when heat is generated in the LED chip and stays in the LED chip for a long time, dislocations and mismatches occur in the crystal structure of the LED chip.

Accordingly, in the related art, techniques for promoting the release of heat generated from the LED chip have been proposed. Among them, instead of mounting the LED chip on the lead frame, an LED package in which a heat dissipation slug having excellent thermal conductivity is additionally installed inside the body, and the LED chip is mounted on the heat dissipation slug. Such a conventional LED package is arranged so that the heat dissipation slug is in contact with the printed circuit board, and heat of the LED chip is mainly transmitted to the printed circuit board through the heat dissipation slug.

However, in the conventional LED package, since the heat dissipation path is concentrated on the printed circuit board having high heat resistance, there is a big limitation in improving the heat dissipation efficiency. In addition, the conventional method of adding a component for heat dissipation has a limitation that the heat dissipation effect is not so great compared to the increase in the cost of the additional installation of the component.

In particular, in the lead frame structure, the bottom surface is flat when trimming and forming, so there is a limit to increasing the heat dissipation area for heat dissipation. If the bottom surface is widened to increase the heat dissipation area, there is a structural problem that the LED package structure becomes larger.

The technical problem to be achieved by the present invention is to provide a heat dissipation LED package capable of smoothly dissipating heat by forming a groove portion for increasing the heat dissipation area in the lead frame disposed on the bottom surface.

In order to achieve the above technical problem, the heat dissipation LED package according to an embodiment of the present invention is an LED chip; A body formed to surround the LED chip; And a lead frame having one end disposed in close proximity and the other end protruding outward from the body to extend to the bottom surface of the body, wherein the lead frame disposed on the bottom surface has a groove portion for widening a heat dissipation area. It is done.

Here, a receiving portion for receiving the groove portion may be formed on the bottom surface of the body. In addition, a protrusion formed on a surface of the printed circuit board on which the body is mounted is inserted into the groove, and the protrusion may be molded by molding a thermally conductive material.

According to the embodiment of the present invention, as the groove is formed in the lead frame disposed on the bottom surface of the body, the heat dissipation area can be widened, thereby easily dissipating heat of the LED chip. In this way, as the heat dissipation area is increased, heat dissipation may be improved to ensure reliability of the LED package. In addition, it is possible to greatly reduce performance degradation and lifespan reduction due to degradation of the LED chip without changing the size of the package.

1 is a view for explaining a heat radiation LED package according to an embodiment of the present invention.

FIG. 2 shows a leadframe and a body before a trim process and a forming process. FIG.

3 is a view for explaining a heat radiation LED package according to another embodiment of the present invention.

Figure 4 is a view for explaining a heat dissipation LED package according to another embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

1: heat dissipation LED package 10: LED chip

20: body 22: housing

221: receiving portion 24: sealing material

30: PCB 31: protrusion

40: lead frame 42: first lead

44: second lead 421, 441: groove portion

W: Bonding Wire

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided as examples to sufficiently convey the spirit of the present invention to those skilled in the art. Accordingly, the present invention is not limited to the embodiments described below and may be embodied in other forms. And, in the drawings, the width, length, thickness, etc. of the components may be exaggerated for convenience. Like numbers refer to like elements throughout.

1 is a view for explaining a heat dissipation LED package according to an embodiment of the present invention, Figure 2 is a view showing a heat dissipation LED package during the trimming and forming process.

As shown in FIG. 1, the heat dissipation LED package 1 according to the present embodiment includes an LED chip 10, a body 20 accommodating the LED chip 10, and the LED chip 10. It includes a lead frame 40 for applying a current. The heat dissipation LED package 1 is mounted on the printed circuit board 30. Although not shown in detail, the printed circuit board 30 includes an electrode pattern (not shown) connected to an end of the lead frame 40.

In this embodiment, the body 20 is composed of a housing 22 and an encapsulant 24. The housing 22 serves to support the lead frame 40 while being made of a resin or ceramic material. In addition, the housing 22 includes an opening formed to be inclined at an upper portion thereof. The LED chip 10 is positioned inside the housing 22 and mounted to the lead frame 40 through the upper opening of the housing 22. . The upper opening of the housing 22 is formed to be inclined, the light reflecting portion is preferably formed on the inclined surface.

The lead frame 40 includes a first lead 42 and a second lead 44. One end of each of the first and second leads 42 and 44 is disposed to face each other in the housing 22, and the other end of the first and second leads 42 and 44 extends to the bottom surface of the housing 22. The first and second leads 42 and 44 extending to the bottom surface are in contact with an electrode on the printed circuit board 30.

In the present embodiment, the LED chip 10 is mounted on the first lead 42 so that one electrode (not shown) of the LED chip 10 and the first lead 42 are electrically connected to each other. The second lead 44 is electrically connected to another electrode (not shown) of the LED chip 10 by a bonding wire w.

The encapsulant 24 is a portion forming the body 20 of the heat dissipation LED package 1 together with the housing 22. The encapsulant 24 is filled in the upper opening of the housing 22 in a molding manner and cured to form the LED chip. Cover 10. The encapsulant 24 is preferably formed of a transparent material such as epoxy, and may include a phosphor for exciting light generated from the LED chip 10, and the phosphor may be used for color conversion of light. . Furthermore, the encapsulant 24 may further include a diffusion material for diffusing light.

In the first and second leads 42 and 44 extending to the bottom surface of the housing 22 of the body 20, grooves 421 and 441 are formed to increase the heat dissipation area, thereby increasing the thermal conductivity. The thermal conductivity is obtained by the following Equation 1, and as shown in Equation 1, the thermal conductivity is proportional to the heat dissipation area.

Thermal Conductivity (P) = Q / t = k * A * (TH-TC) / L

Where Q is the energy transferred as heat, A is the heat dissipation area of the leadframe, L is the thickness of the leadframe, t is the time the heat is transferred, k is the thermal conductivity, TH is the hot site temperature, TC is the low site temperature.

On the other hand, as shown in Figure 2, a pair of receiving portion 221 having a space enough to accommodate the grooves (421, 441) on the bottom surface of the housing 22 before the trim (forming) process and forming (forming) process May be formed, but when the housing 22 is formed, the accommodating part 221 may be formed together to have a space enough to accommodate the grooves 421 and 441. The grooves 421 and 441 are fixed to the pair of accommodating parts 221, which may be performed by a pressing process, but are not necessarily limited thereto. The grooves 421 and 441 define grooves that are concave toward the printed circuit board 30. In addition, the grooves 421 and 441 may be formed in a conical shape so as to be inserted into the receiving portion 221 smoothly, but is not limited thereto.

The grooves 421 and 441 face upwardly with the first and second leads 42 44 and downwardly face the printed circuit board 30 on which the heat dissipation LED package 1 is mounted. The first and second leads 42 and 44 disposed on the bottom surface of the housing 22 except for the grooves 421 and 441 are connected to an electrode on the printed circuit board 30.

At this time, the grooves 421 and 441 may be filled with solder connecting the electrodes of the printed circuit board 30 and the lead frame 40 to each other, but as shown in FIG. The printed circuit board 30 facing may have a protrusion 31 formed by molding a material including a heat radiation material, for example, a thermally conductive material. Accordingly, since heat generated in the LED chip 10 passes through the lead frame 40 and the protrusion 31 continuously, the heat is effectively emitted to the outside, and thus the LED chip according to the heat release delay on the LED chip 10 ( The deterioration of 10) can be largely suppressed.

The heat radiation material is an additive having excellent thermal conductivity, and may be a ceramic additive such as aluminum nitride (AIN) or boron nitride (BN). Therefore, the protrusion part 31 may be formed by injecting a thermally conductive material containing a ceramic additive, such as a silicone resin or an epoxy resin.

Hereinafter, an LED package according to other embodiments of the present invention will be described. In the following description of the embodiments, the foregoing description will be omitted below to avoid duplication, and the member number used in the description of the same or similar members as the previous embodiment will be used the same in the description of the following embodiments.

4 is a view showing a heat dissipation LED package having a lead frame structure different from the previous embodiment.

Referring to FIG. 4, the heat dissipation LED package 1 according to another embodiment of the present invention includes a body 20 having a housing 22 and an encapsulant 24. That is, the body 20 covers the LED chip 10 to support the lead frame 40 while protecting the LED chip 10 mounted on the lead frame 40 while being made of a translucent resin. The lead frame 40 includes a first lead 42 and a second lead 44 spaced apart from the first lead 42, and the LED chip 10 is mounted on the first lead 42. The second lead 44 and the LED chip 10 are electrically connected by a bond wire (W). Although the first and second leads 42 and 44 are shown to be a surface mounting type (SMD) on the printed circuit board 30, the present invention is not limited thereto.

The lead frame 40 protrudes to the outside of the housing 22 to extend to a flat bottom surface of the housing 22, and grooves 422 and 442 are provided in the lead frame 40 disposed on the bottom surface. Is formed. The grooves 422 and 442 are hollow to enter the flat lead frame 40 disposed on the bottom surface. In this case, the grooves 422 and 442 may be formed by an etching process, but are not limited thereto.

Therefore, the heat generated when driving the LED chip 10 can be quickly discharged to the outside while passing through the lead frame 40 formed with the grooves 422 and 442 for widening the heat dissipation area without changing the size of the package. Compared to the frame 40, the heat dissipation area is wider, and thus heat can be effectively discharged.

Claims (4)

LED chip; A body formed to surround the LED chip; And One end is arranged in close proximity, the other end includes a lead frame arranged to protrude out of the body to extend to the bottom surface of the body, The heat dissipation LED package, characterized in that the lead frame disposed on the bottom surface is formed with a groove for increasing the heat dissipation area. The heat dissipation LED package according to claim 1, wherein an accommodating part is formed in the bottom surface of the body to accommodate the groove part. The heat dissipation LED package according to claim 1, wherein the groove has a protrusion formed on a surface of the printed circuit board on which the body is mounted. The heat dissipation LED package according to claim 3, wherein the protrusion is a heat conductive material.