KR20090017346A - LED package with scattering means - Google Patents

Abstract

By distributing a means for scattering light in an encapsulant, an LED package is disclosed that is capable of scattering light widely and sending it out without significant loss of light. The disclosed LED package includes an LED chip that emits light by applying an electric current, a light-transmissive encapsulant formed to cover the LED chip, and reflective particles scattered on or inside the encapsulant to scatter light emitted from the LED chip. Or scattering means such as bubbles.

Description

LED package with scattering means {LED PACKAGE WITH DIFFUSION MEANS}

The present invention relates to a light emitting diode (LED) package, and more particularly, to an LED package including a means for scattering light emitted from an LED chip.

In general, LEDs are devices in which electrons and holes meet and emit light in a P-N semiconductor junction (P-N junction) by applying current. Such LEDs are usually manufactured and used in a package structure in which an LED chip is mounted.

The LED package includes an LED chip, means for applying a current to the LED chip, for example, a lead frame or the like, and an encapsulant for protecting the LED chip from the outside while allowing light emission from the LED chip. do. In the LED package as described above, the LED chip has a light emission characteristic having a high linearity. Due to the luminescent properties of these LED chips, the LED package in which they are incorporated can be useful for, for example, a backlight light source that illuminates a range of specific irradiation surfaces, for example, but it is particularly suitable for illuminating a wide area. However, there is a limit to the use as a decorative lighting fixture.

On the other hand, in the related art, a technique for widely diffusing light from an LED package having a large straightness and a large glare by using an additional mechanism such as a reflector or a reflector has been proposed. However, using such additional fixtures increases the overall size of the lighting device and, furthermore, causes a lot of light loss, greatly reducing the light efficiency. In particular, the conventional LED package has a great limitation in the use as a decorative luminaire in that it is difficult to produce lighting of various forms and / or various colors. In addition, it may also be considered to provide a separate light-transmitting diffusion mechanism in the light path outside the LED package to diffuse the light widely, even in such a case there is a problem that additional space for the installation of the diffusion mechanism is required.

 Accordingly, the technical problem of the present invention is to provide an LED package configured to scatter light widely and emit it to the outside without large loss of light by dispersing means for scattering light in an encapsulant close to the outside.

In addition, another technical problem of the present invention is to provide an LED package capable of producing various colors by a structure in which reflective particles having intrinsic colors are dispersed in an encapsulant.

According to the present invention, an LED chip which is operated to emit light by applying an electric current, a light-transmissive encapsulant formed to cover the LED chip, and scattering means scattered on or inside the encapsulant to scatter light emitted from the LED chip An LED package including a is provided.

According to a preferred embodiment of the present invention, the scattering means is a plurality of reflective particles, the plurality of reflective particles are composed of one kind of particles having the same unique color or two or more kinds of particles having different unique colors. A phosphor is included in the encapsulant between the LED chip and the plurality of reflective particles, and the LED chip and the phosphor are combined to produce white light.

In an alternative embodiment, the scattering means may be a plurality of bubbles scattered inside the encapsulant.

In the above embodiments, the encapsulant includes a first encapsulation portion formed directly on the LED chip and a second encapsulation portion formed on the first encapsulation portion, and the scattering means includes the second encapsulation portion. It is included and separated from the LED chip.

According to the present invention, a LED package having a compact structure, which brightens the surroundings widely without large loss of light, can be implemented. In addition, when using reflective particles having a unique color for scattering light, it can be applied as a decorative luminaire capable of producing a variety of colors.

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 ensure that the spirit of the present invention can be fully conveyed 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 cross-sectional view showing an LED package according to an embodiment of the present invention.

As shown in FIG. 1, the LED package 1 according to the present exemplary embodiment has a package structure including a housing 10. The housing 10 has an open top structure, and has a space therein for accommodating the LED chip 2 and a portion on which the LED chip 2 is mounted.

In this embodiment, a substantially cylindrical heat dissipation slug 20 is inserted into the housing 10 to promote heat dissipation of the LED chip 2 and to suppress degradation of performance and lifespan of the LED chip 2. The LED chip 2 is attached to the protrusion of the upper end of the heat dissipation slug 20. In the present embodiment, the LED chip 2 is attached on the heat dissipation slug 20, but, on the other hand, the LED chip 2 is attached to any one of the first and second lead frames 32 and 34 with the heat dissipation slug omitted. 2) can be attached.

The LED package 1 includes first and second lead frames 32 and 34 for applying current to the LED chip 2. The first and second lead frames 32 and 34 are electrically connected to the LED chip 2 by bonding wires W while being supported by the housing 10. A translucent encapsulant 40 covering the LED chip 2 is formed in the upper opening of the housing 10 to protect the LED chip 2. In the present embodiment, the encapsulant 40 is formed of a light-transmissive resin such as epoxy or silicon, for example, a first encapsulation portion 42 formed directly on the LED chip 2 and the first encapsulation material. The second encapsulation part 44 is formed on the first encapsulation part 42. In this case, materials of the first encapsulation part 42 and the second encapsulation part 44 may be different from each other.

The encapsulant 40 is provided with scattering means for scattering and emitting the light immediately before the light generated from the LED chip 2 is emitted to the outside. In the present embodiment, the scattering means is made of reflective particles 52, 54, as can be seen in the enlarged view of Figure 1, included in the second encapsulation 44 of the encapsulant 40 do. In this case, it may be considered to form the reflective particles 52 and 54 on the outer surface of the second encapsulation 44.

As shown in the enlarged view of FIG. 1, the second encapsulation portion 44 is provided with a plurality of reflective particles 52 and 54 scattering light to be emitted to the outside. In the present embodiment, the plurality of reflective particles 52 and 54 include two or more reflective particles having different intrinsic colors. In FIG. 2, two reflective particles, that is, a gold foil particle 52 and a silver foil particle 54 are shown to be provided to the second encapsulation 44, but other reflective particles of another material are added. It may be provided as. It is also conceivable to use only one reflective particle having the same intrinsic color.

In the present embodiment, the reflective particles 52 and 54 are only included in the second encapsulation 44 without being included in the first encapsulation 42, which is the LED chip 2 and the reflective particles 52. , 54, to prevent light loss caused by the light emitted from the LED chip 2 directly hitting the reflective particles 52, 54, furthermore, the reflective particles 52, 54 and the LED chip ( 2) It prevents the deterioration of electrical performance which may be caused by the contact between them.

FIG. 2 is a view for explaining another embodiment of the present invention. Referring to FIG. 2, reflective particles 52 and 54 are scattered on the second encapsulation portion 44 of the encapsulant 40 as in the previous embodiment. On the other hand, the first encapsulation portion 42 is provided with a phosphor 62 combined with the LED chip 2 to produce white light. For example, white light can be produced by placing a phosphor 62 emitting yellow-green or yellow on the upper part of the LED chip 2 emitting blue light as an excitation light source. In addition, a combination of various LED chips 2 and phosphors 62 can produce white light.

At this time, since the phosphor 62 is positioned between the LED chip 2 under the first encapsulation part 42 and the reflective particles 52 and 54 in the second encapsulation part 44, the lower part of the encapsulation part 42 is provided. The white light generated by the light scatters by colliding with the reflective particles 52 and 54 of the second encapsulation portion 44. The reflective particles 52, 54 have, for example, an intrinsic color of gold, silver or some other color, so that they collide with white light and the white light is emitted to appear in its own intrinsic color. Accordingly, the LED package 1 of the present embodiment can emit light of various colors changed by the reflective particles 52 and 54 to the outside, unlike the conventional LED package emitting monochromatic light. By this, various lighting can be produced.

3 is a view for explaining another embodiment of the present invention. Referring to FIG. 3, the LED package 1 according to the present embodiment includes an encapsulant 40 including the first encapsulation part 42 and the second encapsulation part 44, as in the previous embodiment. However, unlike the previous embodiment, the second encapsulation 44 has a structure in which bubbles 56 are scattered by means of refracting or scattering light. The bubbles 56 have a refractive index different from that of the resins forming the second encapsulation 44, particularly epoxy or silicone resin. Therefore, when the light hits the bubble 56, the light does not pass through the bubble 56 and is scattered.

Various methods of dispersing the bubble 56 in the encapsulant 40 may be considered. One of the methods may include forming the first encapsulation portion 42 first, and then using a resin having a large number of bubbles. The second encapsulation portion 44 is formed, and the other is to blow bubbles into the resin injected or coated to cover the LED chip 2 before the resin solidifies. For this purpose injection techniques using injection needles can be used.

In the accompanying drawings to illustrate the present invention is shown as two encapsulation of the encapsulant, the present invention is not limited to the number of encapsulation, preferably, the encapsulant may be composed of two or more encapsulation, Scattering means is provided in any one of the sealing portions. It is also contemplated that an encapsulant that is not partitioned into a plurality of encapsulations, that is, consisting of a single encapsulation, is used in the LED package of the present invention.

1 is a cross-sectional view for explaining an LED package according to an embodiment of the present invention.

Figure 2 is a cross-sectional view for explaining an LED package according to another embodiment of the present invention.

3 is a cross-sectional view for explaining an LED package according to another embodiment of the present invention.

<Code Description of Main Parts of Drawing>

2: LED chip 40: encapsulant

42: first sealing portion 44: second sealing portion

52, 54: Reflective particle 56: Bubble

Claims (8)

An LED chip which emits light by application of current; A translucent encapsulant formed to cover the LED chip; Scattering means scattered on the inside or the surface of the encapsulation material to scatter light emitted from the LED chip; Including LED package. The LED package of claim 1, wherein the scattering means is a plurality of reflective particles. The LED package according to claim 2, wherein the plurality of reflective particles are made of one particle having the same unique color or two or more particles having different unique colors. The LED package of claim 3, wherein a phosphor is included in the encapsulant between the LED chip and the plurality of reflective particles. The LED package according to claim 4, wherein the LED chip and the phosphor are combined to produce white light. The LED package according to claim 1, wherein the scattering means is a plurality of bubbles scattered in the encapsulant. The method of claim 2 or 6, wherein the encapsulant includes a first encapsulation portion formed directly on the LED chip, and a second encapsulation portion formed on the first encapsulation portion, wherein the scattering means is the second encapsulation portion. Included in, LED package, characterized in that separated from the LED chip. The LED package according to claim 1, wherein the encapsulant includes a phosphor.

Images