KR20150116527A - High-efficiency LED package manufacturing method - Google Patents

Abstract

The present invention relates to a high-efficiency LED package manufacturing method capable of improving efficiency by coating the inner side of an LED package with silicon resins in which a phosphor is dispersed and locating the phosphor on the upper side of an LED chip after a sintering process by precipitating the phosphor dispersed in the silicon downwards and preventing the silicon resins in the package from flowing out to the outside by surface tension if the package is reversed and sintered.

Description

TECHNICAL FIELD [0001] The present invention relates to a high-efficiency LED package manufacturing method,

The present invention relates to a method of manufacturing a high efficiency light emitting diode package, and more particularly, to a method of manufacturing a white light emitting device using a light emitting diode (LED) To a method of manufacturing a high-efficiency light emitting diode package.

2. Description of the Related Art Generally, a light emitting diode has excellent monochromatic peak wavelength, excellent light efficiency and miniaturization, and is widely used as various display devices and light sources. In particular, white light emitting diodes have been actively developed as high power, high efficiency light sources that can replace backlights of illumination devices or display devices.

As a method of realizing such a white light emitting diode, a wavelength conversion method of applying a phosphor to a near-ultraviolet to blue light (370 nm to 480 nm) light emitting diode and converting it into white light is mainly used.

1A is a cross-sectional view showing a white light emitting diode package 10 manufactured according to a conventional method.

1A, the white light emitting diode package 10 includes a package substrate 11 on which two lead frames 13a and 13b are formed and a blue light emitting diode chip 12 mounted on a cap structure 12 of the package substrate 11. [ (15). The light emitting diode chip 15 has a flip chip structure including a light emitting diode 15a and a chip substrate 15b and is formed on the chip substrate 15b and connected to the positive electrode of the light emitting diode 15 (Not shown) may be connected to the upper ends of the lead frames 13a and 13b by wires 14a and 14b, respectively.

A molding portion 19 containing a Y-Al-Ga (YAG) -based phosphor is formed in the cap structure 12 so as to surround the blue LED chip 15. The phosphor powder 18 distributed in the molding part 19 converts a part of the blue light emitted from the LED 15a into yellow light and the converted yellow light can be emitted to the desired white light in combination with the unconverted blue light have.

In general, the wavelength converting molding part 19 can be formed by using a dispensing process for a liquid resin in which phosphor powders are uniformly dispersed.

However, since the conventional dispensing process uses a liquid resin as shown in the cross-sectional view of FIG. 1B, there is a problem that the phosphor powder precipitates in the process of curing the liquid resin. Even in the side region of the light emitting diode chip marked with A, there is almost no phosphor powder, so that the ratio of blue light emitted without wavelength conversion can become excessively high. This requires a larger amount of phosphor powder. As a result, the light emission luminance is lowered, and the color temperature of the light differs depending on the deflection angle, resulting in a color uneven phenomenon which is partially white or white.

In addition, in the case of providing a reflective surface for improving brightness on the inner surface of the cap structure or the substrate, the precipitated phosphor powder adheres to the reflective surface to reduce the reflection effect, do.

In the case of using various phosphor powders in combination, the precipitation phenomenon of the above-described phosphor powders becomes a more serious problem. For example, when a white light emitting diode is manufactured using a mixture of ultraviolet LEDs and red, green, and blue phosphor powders having an appropriate blending ratio, since different specific gravities and particle sizes are provided for each phosphor, do.

That is, when a silicone resin having a phosphor dispersed therein is applied to the LED, the phosphor precipitates on the bottom surface, and the phosphor precipitated on the bottom surface does not excite the wavelength emitted from the blue chip. Therefore, more phosphors must be dispersed in consideration of the precipitation, which leads to an increase in the amount of the phosphor used.

In order to overcome such a problem, a structure for a remote phosphor type multi-layer package in which a silicon resin layer in which phosphors are not dispersed is stacked as a single layer and a phosphor is dispersed in two layers as shown in FIG. 2 has been developed , There is a problem that the first layer and the second layer are peeled off after being used for a long period of time when they are piled up in two layers, and the process is made in two steps, which increases the production process steps and costs.

Korean Registered Patent No. 10-0674831 [Title of the invention: White light emitting diode package and its manufacturing method] Korean Unexamined Patent Publication No. 2003-0088882 [Title of the invention: white light emitting device]

In order to solve such a problem, the present invention relates to a method of manufacturing a light emitting diode (LED) package in which a silicone resin in which phosphors are dispersed is applied to an LED package, The present invention provides a method of fabricating a highly efficient light emitting diode package in which phosphors dispersed downward are positioned on a light emitting diode (LED) chip after firing.

A method of manufacturing a high efficiency light emitting diode package according to an embodiment of the present invention includes the steps of applying a silicone resin dispersed with a phosphor to a lead frame to which a light emitting diode chip is coupled and fixing the light emitting diode package coated with the silicone resin to a jig And locating the jig in a firing furnace and firing it.

When the silicone resin in which phosphor is dispersed is applied to the inside of a light emitting diode (LED) package and the light emitting diode (LED) package is fired and turned upside down, the silicone resin in the package does not exit outside due to surface tension, And the phosphor is deposited on the light emitting diode (LED) after the firing so that the efficiency can be improved.

In addition, the present invention makes it possible to manufacture a light emitting diode package having an average total light flux (.mu.v (mlm)) of 11,182, thereby increasing the light flux of the package of the light emitting diode manufactured by the general manufacturing method by about 7% Is located more on the silicon resin package than the light emitting diode package, thereby further improving the light conversion efficiency of the photon.

Further, it can be seen that the present invention has a color temperature (CCT) of about 4270, which is shifted toward the upper right side of the color coordinate system in the direction of Worm White, compared with 4580 of the general manufacturing method. The phosphor is positioned more on the silicon resin package than the light emitting diode package, and the light conversion efficiency of the photon can be further improved.

Further, according to the present invention, more phosphors are positioned on the upper part of the silicon resin in the package, and thus the light conversion efficiency of the phosphor is improved, and finally the light emitting diode efficiency is about 62.1 lm / W, W is about 8.1% higher than that of W.

1A is a schematic view showing a cross section of a conventional white light emitting diode package.
FIG. 1B is a SEM photograph of a real white light emitting diode package of a similar type to FIG. 1A.
2 is a process sectional view illustrating a method of manufacturing a white light emitting diode package in a multilayer structure.
3 is a cross-sectional view illustrating a method of manufacturing a high-efficiency light emitting diode package according to the present invention.
FIG. 4 is a graph comparing wavelengths of a light emitting diode package fired by a general method and a light emitting diode package manufactured according to the present invention.
5 is a color coordinate graph.

It is noted that the technical terms used in the present invention are used only to describe specific embodiments and are not intended to limit the present invention. In addition, the technical terms used in the present invention should be construed in a sense generally understood by a person having ordinary skill in the art to which the present invention belongs, unless otherwise defined in the present invention, Should not be construed to mean, or be interpreted in an excessively reduced sense. In addition, when a technical term used in the present invention is an erroneous technical term that does not accurately express the concept of the present invention, it should be understood that technical terms can be understood by those skilled in the art. In addition, the general terms used in the present invention should be interpreted according to a predefined or prior context, and should not be construed as being excessively reduced.

Furthermore, the singular expressions used in the present invention include plural expressions unless the context clearly dictates otherwise. In the present invention, terms such as "comprising" or "comprising" and the like should not be construed as encompassing various elements or various steps of the invention, Or may further include additional components or steps.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals refer to like or similar elements throughout the several views, and redundant description thereof will be omitted.

In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. It is to be noted that the accompanying drawings are only for the purpose of facilitating understanding of the present invention, and should not be construed as limiting the scope of the present invention with reference to the accompanying drawings.

3 is a cross-sectional view illustrating a method of manufacturing a high-efficiency light emitting diode package according to the present invention.

As shown in FIG. 3, first, a silicone resin 140 in which phosphors 130 are dispersed is applied to a lead frame 120 to which a light emitting diode chip 110 is coupled. Then, the light emitting diode package coated with the silicone resin 140 is fixed to the jig with the jig inverted, and the jig is placed in the baking furnace and baked. At this time, the leveling process is performed at a low temperature so that the phosphor 130 can be precipitated to the lower end, and the firing process is completed at a high temperature. This completes the Remote Phosphor type LED package.

Hereinafter, the operation and effect of the present invention will be described in more detail with reference to embodiments of the present invention.

(Example)

In this embodiment, the silicone resin 140 dispersed in the phosphor 130 is coated on the lead frame 120 coupled with the LED chip 110, and then the LED chip 140 is placed upside down on the jig and placed in the baking furnace. When the leveling process is completed, the temperature of the firing furnace is raised to a high temperature so that firing is performed at a high temperature.

The following table shows the results of fabricating a light emitting diode package according to a manufacturing method to which the present invention is applied.

That is, as can be seen from the above table, the light emitting diode package manufactured by the manufacturing method according to the present invention has the following characteristics.

(X, y) values were about 0.36 and 0.34, which were 0.35 and 0.33 in the comparative example, respectively. In the color coordinate graph of Fig.

Moving to the upper right corner in the color coordinate shows that the yellow color is thicker, which means that the yellow phosphor moves more toward the top of the package and is excited more by the actual photon.

The color temperature (CCT) was about 4270, the color rendering index (Ra) was 79, and the efficiency of the LED fabricated according to the present invention was about 62 lm / W.

(Comparative Example)

In this comparative example, a silicone resin dispersed with a phosphor is applied to the lead frame, which is the same as in the above-described embodiment, and then a sintering process is performed by a general method. The results obtained by the sintering process of the general method are shown in the following table .

As can be seen from the above table, the light emitting diode package manufactured by a general manufacturing method to which the present invention is not applied has the following characteristics.

The total luminous flux (Фv (mlm)) was about 10,000 in all four packages and the average (AVG) value was 10,461. It can be seen that the values of the color coordinates (x, y) are about 0.35 and 0.33, which are located at the lower left in comparison with Examples 0.36 and 0.34. The color temperature (CCT) was about 4580 and the color rendering index (Ra) was 79. The efficiency of the LED fabricated by a general manufacturing method without the present invention was found to be about 57 lm / W on average.

FIG. 4 is a graph comparing wavelengths of a light emitting diode package fired by a general method and a light emitting diode package manufactured according to the present invention.

As shown in FIG. 4, intensity of light emitted from the light emitting diode fabricated by the manufacturing method of the present invention is increased in the wavelength range of 500 to 700 nm as compared with the package of the general manufacturing method.

It can be seen that the phosphor is located more on the light emitting diode package, and the photon excites the yellow phosphor more, and the intensity of the yellow wavelength range of 500 to 700 nm is further increased.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or essential characteristics thereof. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

110: Light emitting diode chip
120: Lead frame
130: Phosphor
140: silicone resin

Claims (1)

Applying a silicone resin dispersed with a phosphor to a lead frame to which a light emitting diode chip is coupled; And
And a step of fixing the light emitting diode package coated with the silicone resin to the jig with the jig being inverted and placing the jig in the baking furnace and firing the package.

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