KR20150012680A - Light emitting diode package having an excellent heat dissipation capability - Google Patents

Abstract

The light emitting diode package of the present invention comprises a substrate; A light emitting diode chip mounted on the substrate; And a phosphor layer and a silicon mixture layer applied to the light emitting diode chip, wherein the mixture layer of the phosphor and the silicon layer is reduced in thickness by 10% or more by curing.
According to the present invention, since the thickness of the mixture layer of phosphor and silicon is drastically reduced by curing, heat generated from the light emitting diode chip can be easily radiated through the thin layer of the mixture to reduce the temperature of the light emitting diode package .

Description

[0001] LIGHT EMITTING DIODE PACKAGE HAVING AN EXCELLENT HEAT DISPOSABLE CAPABILITY [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting diode package, and more particularly to a light emitting diode package having excellent heat dissipation characteristics.

A light emitting diode (LED) refers to a semiconductor light emitting device that emits light when electrons and holes recombine at a P-N semiconductor junction by applying a current. The light emitting diode is environmentally friendly, is driven at a low voltage, has a long lifetime, and has been mainly applied to simple information display such as a display lamp. In recent years, the development of industrial technology, in particular, the development of information display technology and semiconductor technology, has led to the use of light emitting diodes in various fields such as display fields, lighting devices, automobile head lamps and projectors.

Recently, the technical problem of the products using the light emitting diode is to prevent deterioration of the performance or product life due to the heat generation of the light emitting diode product, and research on a technology for reducing the size of the light emitting diode package and having a smooth heat dissipation structure is actively conducted It is progressing. Widely used as one of the structures and methods for improving the heat dissipation property is a COB (Chip on Board) type light emitting diode package technology in which the light emitting diode chip is directly mounted on a printed circuit board. The COB type light emitting diode package technology reduces the heat escape path from the chip, increases the heat radiation effect, and reduces the height of the package itself.

The COB type light emitting diode package may include a light emitting diode chip mounted on a lower substrate (e.g., MCPCB) having a plurality of electrode patterns using a die adhesive. A phosphor layer for changing the wavelength of the light emitted from the light emitting diode chip may be formed on the light emitting diode chip in various ways. In other words, the COB type light emitting diode package can be manufactured to emit white light by mixing blue light by the blue light emitting diode chip and light passing through the yellow phosphor layer.

However, in the COB type light emitting diode package, the phosphor layer formed on the light emitting diode chip significantly affects the heat dissipation characteristics of the light emitting diode package. Therefore, when the light emitting diode package is applied to a lighting apparatus, a backlight unit, The thickness of the layer is preferably as thin as possible within the range allowed by the process.

For example, Korean Patent Laid-Open Publication No. 2009-0078912 discloses a plasma display panel comprising a base substrate; A dam having a cavity formed at a central portion thereof and provided on the base substrate; At least two light emitting diode chips disposed on the base substrate and surrounded by the dam; And a phosphor layer filled in the cavity. The above-mentioned patent has the effect of forming a phosphor layer having a uniform thickness by forming a phosphor layer by using a dam after arranging a plurality of light emitting diode chips. However, since the heat dissipation characteristic Improvement is not disclosed.

More specifically, another conventional COB type light emitting diode package will be described with reference to the drawings. Fig. 1 shows an example of a COB type light emitting diode package. 1, a COB type light emitting diode package includes a lower substrate including a base metal 10, an insulating layer 11 and a wiring layer 12, and a lower substrate bonded to the upper portion of the lower substrate by a die adhesive 14 A phosphor layer 20 which encapsulates the light emitting diode chip 1 integrally with the bladder diode chip 1 and the wiring 15 and changes the wavelength of the light emitted from the LED chip 1; A dam 13 and a heat sink 16 formed below the base metal 10 and radiating heat generated from the light emitting diode chip.

The COB type light emitting diode package can totally emit white light by mixing blue light by the blue light emitting diode chip 1 and light passing through the phosphor layer 20, for example. However, due to the presence of the phosphor layer 20 formed to a height as high as the height of the dam, heat generated in the light emitting diode may not be efficiently diffused.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems of the prior art, and an object of the present invention is to reduce the thickness of a mixture layer of phosphor and silicon formed on an LED chip, thereby improving the heat radiation performance of the LED package.

According to an aspect of the present invention, there is provided a light emitting diode package comprising: a substrate; A light emitting diode chip mounted on the substrate; And a phosphor layer and a silicon mixture layer applied to the light emitting diode chip, wherein the mixture layer of the phosphor and the silicon layer is reduced in thickness by 10% or more by curing.

Further, preferably, the thickness of the mixture layer of the phosphor and the silicon can be reduced to 90% or less.

Further, it may further include a dam formed on the substrate and surrounding the light emitting diode chip.

Preferably, a mixture layer of the phosphor and silicon may be formed in the dam.

Further, preferably, the dam may be formed before the mixture layer of the phosphor and the silicon is applied.

Further, preferably, the dam may be formed by a dispenser.

Further, preferably, the mixture layer of the phosphor and the silicon may be formed by a dispenser.

Since the thickness of the mixture layer of the phosphor and silicon is reduced by curing, heat generated from the light emitting diode chip can be easily radiated through the thin layer of the mixture, so that the temperature of the light emitting diode package can be reduced.

The present invention can efficiently radiate heat to the outside through the mixture layer, so that the weight of the heat sink attached to the light emitting diode package can be reduced.

1 is a cross-sectional view of a conventional COB type light emitting diode package.
2 is a perspective view of a COB type light emitting diode package according to the present invention, showing a state before the phosphor and the silicon mixture layer are cured.
3 is a cross-sectional view of a COB type light emitting diode package according to the present invention, showing a state before a phosphor and a silicon mixture layer are cured.
4 is a cross-sectional view of a COB type light emitting diode package according to the present invention, showing a state after the phosphor and the silicon mixture layer are cured.
5 (a) and 5 (b) are photographs of a COB type light emitting diode package according to the present invention, in which FIG. 5 (a) shows the state before curing of the phosphor and the silicon mixture layer, And the state after the curing of the silicon mixture layer.

In an embodiment of the present invention, where a layer, region, pattern or structure is described as being formed "above" or "below" a substrate, layer, region, Quot; directly "or" through another layer ". In addition, the above or below standards are based on drawings.

The thickness and size of each component in the drawings may be exaggerated, omitted, or schematically shown for convenience and clarity of explanation. It should also be understood that the size of each component does not entirely reflect the actual size.

Hereinafter, a light emitting diode package according to the present invention will be described with reference to the accompanying drawings. The embodiments described below are provided as examples so that the technical idea of the present invention can be sufficiently transmitted to the ordinary artisan. Therefore, the present invention is not limited to the embodiments described below, but may be embodied in other forms. In the drawings, the same reference numerals denote the same elements.

FIG. 2 is a perspective view of a COB type light emitting diode package according to the present invention, which shows a state before a phosphor and a silicon mixture layer are cured, and FIG. 3 is a sectional view of a COB type light emitting diode package according to the present invention, Showing the state before the layer is cured.

2 and 3, the COB type light emitting diode package 100 before the phosphor and the silicon mixture layer are cured according to the present invention includes a printed circuit board 110, A wire 150 electrically connecting the light emitting diode chip 140 and the wiring layer 120; a dam 130 surrounding the light emitting diode chip 140; A mixture layer 160 of a phosphor and a silicone formed in the dam 130 and applying the light emitting diode chip 140 and a light emitting diode chip 160 installed at a lower portion of the printed circuit board 110, And a heat sink 170 for dissipating heat to the outside. 2 and 3 illustrate one light emitting diode chip 140 for convenience of explanation, the light emitting diode package typically includes a plurality of light emitting diode chips.

 The printed circuit board 110 includes all kinds of substrates including an electrode or an electrode pattern that can be electrically connected to the LED chip 140. Also, in the present invention, the light emitting diode chip 140 emitting blue light is used, but it should be noted that the present invention is not limited thereto. Although the wire 150 uses gold excellent in electrical conductivity, other metals may be used as needed. The dam 130 is formed to prevent a mixture layer 160 of a phosphor and a silicon to be coated from flowing down, and is generally made of a viscous synthetic resin. The dam 130 is preferably formed before application of the mixture layer 160 of phosphor and silicon for convenience of the process. The dam 130 may be formed on the printed circuit board 110 by a dispenser or may be attached on the printed circuit board 110 with an adhesive. In addition, a heat sink 170 installed at a lower portion of the printed circuit board 110 functions to discharge heat generated from the LED chip 140 to the outside, and in consideration of weight and economical efficiency, Or an aluminum alloy, but may be fabricated using other metals or alloys.

Next, the phosphor and silicon mixture layer 160 applied to the inside of the dam 130 and the light emitting diode chip 140 will be described. As commercially available phosphors, there are YAG (Nichia Japan), TAG (German OSRAM), silicate, and sulfide series. In the present invention, YAG 432 was used as a phosphor.

The silicone resin used as the sealing material was a commercially available silicone resin, and a cyclic silicone resin consisting of a single molecule was used as a solvent to be volatilized during curing. A mixture of a mixture of a mixture of a mixture of a main component (including a solvent) and a curing agent (including a solvent) in a weight ratio of 1: 1, and a phosphor was mixed to prepare a phosphor and a silicone mixture. In the present invention, the ratios of the phosphor and the silicon (the base, the solvent and the curing agent) are mixed at a weight ratio of 1: 9, but the ratio can be adjusted according to the shape of the package or the target color.

4 is a cross-sectional view of a COB type light emitting diode package according to the present invention, which shows a state after a phosphor and a silicon mixture are cured. As can be seen from FIG. 4, it can be seen that the thickness of the mixture layer 160 of phosphor and silicon after curing is reduced. According to the present invention, the thickness of the mixture layer 160 of the phosphor and the silicon after curing may be varied depending on process conditions, and in particular, the thickness of the mixture layer 160 of the phosphor and the silicon may be adjusted by adjusting the addition amount of the solvent, Can be adjusted.

Since the object of the present invention is to maximize the amount of heat dissipated through the mixture layer 160 by reducing the thickness of the mixed layer 160 of phosphor and silicon after curing as described above, The thickness of the phosphor layer 160 is preferably 10% to 90% of the thickness of the mixture layer 160 of the phosphor before curing. When the thickness of the mixture layer 160 of the phosphor after curing is 90% or more of the thickness before curing (in other words, when the thickness of the mixture layer 160 is reduced to less than 10% by curing) It is not preferable because the effect is small. On the other hand, the thinner the thickness of the mixed layer 160 of the fluorescent substance and the silicon after curing, the better the heat radiation performance is. However, for the reasons of the process considering the amount of the solvent to be volatilized during curing, Is preferably limited to 10% of the thickness before curing.

The curing conditions and results will be described below. The thickness of the mixture layer 160 of the phosphor and the silicone coated with the dispenser in the LED chip 140 in the dam 130 was 5 mm and the temperature was increased from room temperature to 160 ° C. in the oven for 30 minutes Maintained at 160 캜 for 2 hours, and then warmed to room temperature for 60 minutes. The amount of the solvent to be volatilized during curing is controlled so that the thickness of the mixture layer 160 of the phosphor and the silicon after curing is reduced by 10%, 30%, 50%, 70%, and 90% .

The temperature in the light emitting surface of the COB type light emitting diode package including samples of the mixture layer 160 reduced in thickness by the curing and the sample with no thickness change before and after the curing according to the prior art, The results are shown in Table 1. The test conditions were such that a current of 560 mA was applied to each sample for 1 hour.

Thickness reduction rate after curing (%)

0
10
30
50
70
90
Temperature (° C) of the light emitting surface

181.9
160.2
140.2
128.0
118.7
103.9

In Table 1, it is a COB type LED package according to the prior art that the thickness reduction rate is 0%, and the temperature at the light emitting surface is about 181.9 占 폚. On the contrary, the temperature of the light emitting surface of the COB type LED package according to the present invention having a thickness reduction ratio of 10% was about 160.2 ° C, and the temperature of the light emitting surface gradually decreased as the thickness reduction rate was increased. Though not shown in Table 1, when the reduction rate of the thickness after curing is less than 10%, it is found that the decrease in temperature is smaller than that in the prior art, which is insufficient for practical application.

In addition, as can be seen from Table 1, in the case of the present invention in which the thickness was reduced by 10% after the curing compared with the prior art in which there was no change in thickness before and after curing, a temperature reduction effect of about 11.9% .

5 (a) and 5 (b) are photographs of a COB type light emitting diode package according to the present invention, in which FIG. 5 (a) shows the state before curing of the phosphor and the silicon mixture layer, And the thickness of the mixture layer of silicon after curing is reduced by 90%. As can be seen in the figure, it can be seen that the thickness of the phosphor and the silicon mixture layer 160 formed at the height of the dam 130 is reduced to such an extent that a plurality of light emitting diode chips 140 are visible after curing. The mixture layer of the phosphor and silicon in the present invention is a mixture of a silicone resin as a main component and a cyclic silicone resin composed of a single molecule as a solvent so that the silicone resin as a main component upon curing reacts with the curing agent to cure, Volatilized without participation and the thickness is reduced.

Although the present invention has been described mainly with respect to a COB type light emitting diode package, the present invention can also be applied to a surface mount type light emitting diode package.

It will be appreciated by those of ordinary skill in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof.

Therefore, it should be understood that the above-described embodiments are illustrative and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications that come within the meaning and scope of the appended claims and their equivalents should be construed as being included within the scope of the present invention.

100: Light emitting diode package
110: printed circuit board
120: wiring layer
130: dam
140: Light emitting diode chip
150: wire
160: Fluorescent layer coating (mixture layer of phosphor and silicon)
170: Heatsink

Claims (7)

Board;
A light emitting diode chip mounted on the substrate; And
A phosphor layer and a silicon mixture layer applied to the light emitting diode chip,
Wherein the mixture layer of the phosphor and the silicon is reduced in thickness by 10% or more by curing. The method according to claim 1,
Wherein the thickness is reduced to 90% or less. 3. The method according to claim 1 or 2,
And a dam formed on the substrate and surrounding the light emitting diode chip. The method of claim 3,
Wherein a mixture layer of the phosphor and silicon is formed inside the dam. The method of claim 3,
Wherein the dam is formed before a mixture layer of the phosphor and the silicon is applied. The method of claim 3,
Wherein the dam is formed by a dispenser. 3. The method according to claim 1 or 2,
Wherein the mixture layer of the phosphor and the silicon is formed by a dispenser.

Images