KR100849829B1 - Light emitting diode packet having wide beam angle - Google Patents

Abstract

The present invention relates to an LED package with improved directivity angle. The LED package of the present invention is disposed spaced from each other, the first lead frame and the second lead frame of the thermal and electrical conductor; An LED chip electrically connected to the first lead frame and the second lead frame; A package surrounding at least a portion of the first and second lead frames, protruding an extension of the first lead frame and an extension of the second lead frame to an outside, and an inclined inner surface forming a cup around the LED chip; main body; A first encapsulation portion which at least partially fills the cup portion while encapsulating the LED chip; And a second encapsulation part having a refractive index greater than that of the first encapsulation part, and disposed in a cup part of the main body at an upper layer of the first encapsulation part, wherein the first lead frame includes a base on which the LED chip is mounted and an outer side from the base. A connecting portion extending obliquely upwardly and extending horizontally again from the connecting portion, wherein the first encapsulation portion and the second encapsulation portion are inclined toward the inclined inner surface of the package body from the LED chip based on the difference in refractive index. It is configured to emit at least a portion of the traveling light to the outside without hitting the inclined inner surface to increase the direct angle.

LED, Package, Directional Angle, Refractive Index, Light Diffusion

Description

Light Emitting Diode Package with Wide Orientation Angle {LIGHT EMITTING DIODE PACKET HAVING WIDE BEAM ANGLE}

The present invention relates to a light emitting diode, and more particularly, to a light emitting diode package having improved directivity angle of emitted light.

Light emitting diodes, or LEDs (Light Emitting Diodes), are semiconductor devices for generating light of various colors when a current is applied. The color of light generated by the LED is mainly determined by the chemical constituents of the semiconductor of the LED. The demand for these LEDs is steadily increasing because they have several advantages over filament-based light emitting devices, such as long life, low power, excellent initial driving characteristics, high vibration resistance, and high tolerance for repetitive power interruptions.

Such LEDs are used in the form of packages, and one example of a prior art LED package is shown in cross section in FIG.

Referring to FIG. 1, the LED package 10 includes a pair of conductive patterns 14 and 16 formed on the substrate 12 and an LED chip 18 mounted on the conductive pattern 14. The LED chip 18 is usually electrically connected to the conductive patterns 14 and 16 by wires (not shown). The package sidewall 20 is formed around the LED chip 18, and a transparent resin is filled in the concave cup portion formed by the package sidewall 20 to form the encapsulation portion 22.

The LED package 10 of this configuration is configured to emit upward the light generated from the LED chip 18 at a predetermined angle. However, there is a disadvantage that the upward emission angle of light is limited.

As shown in FIG. 1, the LED chip 18 operates to generate light at its focal point F. At this time, the light L1 is emitted upward at a predetermined angle α with respect to the axis A, which is the normal of the LED chip 18, and the light L2 is an angle β larger than the angle α with respect to the axis A. Is emitted upwards). In this case, the light L1 is emitted to the outside through the top surface of the encapsulation portion 22, and the light L2 is reflected on the side wall 20 and then upwardly emitted. Therefore, the angle α becomes the orientation angle of the LED package 10.

If the direction angle is small, the amount of light hitting the side wall 20 increases, resulting in a decrease in the overall light emission efficiency. In addition, since the emission of light is limited to a narrow range, it is not suitable for lighting using a plurality of LED packages 10. Therefore, it is desirable to be able to increase the orientation angle.

This orientation angle is mainly determined by the height of the side wall 20 and the width of the cup portion. For example, by lowering the height of the side wall 20 or increasing the width of the cup part, the direction angle may be increased. However, since the height of the side wall 20 is required to a certain value in consideration of the process conditions, there is a limit to reducing it. In addition, increasing the width of the cup portion is also undesirable because the volume of the LED package 10 also increases.

Meanwhile, a method of protruding the encapsulation part 22 in a dome shape onto the sidewall 20 in order to increase the direction angle may be applied. However, this requires dotting the resin, which is disadvantageous in that the process is difficult and the number of detailed steps is increased.

The present invention has been made to solve the above-mentioned problems of the prior art, an object of the present invention is to provide a LED package that improves the directivity of the light by placing the first and second encapsulation with different optical characteristics in the lower and upper layers; To provide.

Embodiments of the present invention for achieving the above object are arranged at intervals from each other, the first lead frame and the second lead frame made of a thermal and electrical conductor; An LED chip electrically connected to the first lead frame and the second lead frame; A package surrounding at least a portion of the first and second lead frames, protruding an extension of the first lead frame and an extension of the second lead frame to an outside, and an inclined inner surface forming a cup around the LED chip; main body; A first encapsulation portion which at least partially fills the cup portion while encapsulating the LED chip; And a second encapsulation part having a refractive index greater than that of the first encapsulation part, and disposed in a cup part of the main body at an upper layer of the first encapsulation part, wherein the first lead frame includes a base on which the LED chip is mounted and an outer side from the base. A connecting portion extending obliquely upwardly and extending horizontally again from the connecting portion, wherein the first encapsulation portion and the second encapsulation portion are inclined toward the inclined inner surface of the package body from the LED chip based on the difference in refractive index. The present invention relates to an LED package which is configured to emit at least a portion of the traveling light to the outside without hitting the inclined inner surface to increase the directivity angle.

In the embodiment of the present invention, the second encapsulation portion is characterized in that it contains a filler for increasing the refractive index.

In the embodiment of the present invention, the second encapsulation portion is protruded over the upper end of the package body in the form of a dome.

In an embodiment of the present invention, the second encapsulation portion includes a light diffusing agent.

In an embodiment of the present invention, the light diffusing agent is at least one selected from the group consisting of a polymer, an opal mineral, SiO ₂ , and TiO ₂ .

In an embodiment of the present invention, the first encapsulation portion includes a light diffusing agent, and the second encapsulation portion is attached to an upper surface of the first encapsulation portion to protrude beyond the upper end of the package body in a dome shape.

According to the LED package of the present invention, by directing the first and the second encapsulation portion having different optical characteristics in the lower layer and the upper layer, it is possible to improve the directing angle of the light. Specifically, a high refractive index second encapsulation is disposed on the first encapsulation having a low refractive index to adjust the angle when light is incident from the first encapsulation to the second encapsulation and emitted from the second encapsulation to the outside. You can increase the angle. Moreover, the above-mentioned effect can also be acquired by increasing the refractive index of a 2nd sealing part by adding the refractive index filler to a 2nd sealing part. In addition, the directivity may be further increased by mixing the light diffusing agent in the first encapsulation portion of the lower layer and configuring the second encapsulation portion of the upper layer in a dome shape.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

2 is a longitudinal sectional view of the LED package according to the first embodiment of the present invention. Referring to FIG. 2, the LED package 100 of the present invention may be mounted on and electrically connected to the first and second lead frames 110 and 120 and the first lead frame 110 disposed to face each other. 130 and a package body 140 which is a sidewall for fixing the first and second lead frames 110 and 120.

The first LED frame 110 has a base 112 on which the LED chip 130 is mounted, a connection portion 114 extending obliquely upwardly outward from the base 112 and an extension extending horizontally again from the connection portion 114. Section 116. The base 112 is mounted with an LED chip 130 and electrically connected by wires (not shown) or solder bumps. The connection part 114 and the extension part 116 are surrounded by the package main body 140 and fixed, and the end of the extension part 116 protrudes out of the package main body 140. In this way, the lead frame 110 is firmly fixed to the package body 140 while effectively dissipating heat from the LED chip 130 to the outside.

In addition, the second lead frame 120 includes a base 122 connected to the LED chip 130 by a wire 132, a connecting portion 124 extending upwardly inclined outward from the base 122, and the connecting portion 124. And an extension 126 extending horizontally again from. Since the second lead frame base 122 has an upper surface having the same height as the first lead frame base 112, fabrication of the entire lead frames 110 and 120, connection of the wires 132, and packaging are easy. Do. In addition, since the connection part 124 and the extension part 126 are surrounded by the resin of the package main body 140 and the ends of the extension part 126 protrude out of the package main body 140, the second lead frame 120 is packaged. It is firmly fixed to the main body 140.

The package body 140 forms a concave cup portion surrounding the LED chip 130 while fixing the first and second lead frames 110 and 120. The cup portion is formed by the inner inclined surface 142 of the package body 140. In the present embodiment, the package body 140 is preferably formed of a resin, but is not necessarily limited thereto. For example, it may be formed of a ceramic substrate and sidewalls as shown in FIG. 1.

First and second encapsulation parts 150 and 160 are formed in the cup part formed by the inner inclined surface 142. The first and second encapsulation parts 150 and 160 are formed by filling a transparent resin into a cup part and then curing the cup. In this case, the resin of the first encapsulation part 150 has a lower refractive index than the resin of the second encapsulation part 160.

Meanwhile, although the LED chip 130 is illustrated as a vertical structure LED chip electrically connected to the first lead frame base 112 by solder bumps (not shown), the LED chip 130 may be connected by a wire (not shown).

An effect obtained when the refractive index of the first encapsulation part 150 is smaller than the refractive index of the second encapsulation part 160 will be described with reference to FIG. 3. The LED package 100 shown in FIG. 3 has the same configuration as that shown in FIG.

In the LED package 100 as described above, when the LED chip 130 operates so that light having a predetermined angle β from the focal point F with respect to the axis A which is the normal line of the chip 130 is emitted upward. If the first and second encapsulation portions 150 and 160 have the same refractive index, the light will hit the inclined surface 142 and be reflected. This is indicated by a dotted line by the reference numeral L '.

However, as in the present invention, if the refractive index of the first encapsulation unit 150 is smaller than the refractive index of the second encapsulation unit 160, the light is the first encapsulation unit 150, as indicated by reference numeral L indicated by a solid line. First refraction at the interface between the second encapsulation 160 and the second refraction at the interface between the second encapsulation 160 and the external medium, for example, air, is emitted to the outside.

Comparing the LED package 100 of the present invention with the LED package 10 of the prior art shown in Figure 1 it can be clearly seen the difference. To this end, the interval between the inclined surface 142 of the LED package 100 of the present invention is equal to the width of the cup portion of the LED package 10 of Figure 1, the height of the inclined surface 142 of the LED package 100 is shown in FIG. Assume that it is equal to the height of the side wall 20 of the LED package 10 of 1. That is, it is assumed that the LED package 100 of the present invention has the same emission window as the LED package 10 shown in FIG. In this way, the emission angle β of FIG. 3 becomes equal to the emission angle β of FIG. 1. However, at the same emission angle β, the LED package 100 of the present invention emits light upwards without hitting the inclined surface, while the LED package 10 of FIG. It will hit the slope. It can be seen that the above angle β is within the range of the directivity angle in the LED package 100 of the present invention, but outside the range of the directivity angle α in the LED package 10 of FIG. 1. As a result, the LED package 100 of the present invention is increased in orientation angle compared to the LED package 10 of the prior art.

As such, when the directivity angle is increased, the light extraction efficiency may be increased and the directivity characteristic may be further improved.

An LED package 100-2 according to a second embodiment of the invention is shown in cross section in FIG. 4.

Referring to FIG. 4, the LED package 100-2 according to the present embodiment has the LED of FIG. 2 except that the second encapsulation portion 160-2 protrudes in a dome shape over the upper end of the package body 140. It is the same structure as the package 100. The rest of the configuration is the same as that of the LED package 100 and therefore the same reference numerals will be given and the description will not be repeated.

In the LED package 100-2 of the present exemplary embodiment, since the second encapsulation portion 160-2 has a refractive index greater than that of the first encapsulation portion 150, the LED package 100-2 is formed to have a dome shape, and thus a direction of the light generated by the LED chip 130 is obtained. Can be increased further.

An LED package 100-3 according to a third embodiment of the invention is shown in cross section in FIG. 5.

Referring to FIG. 5, the LED package 100-3 according to the present exemplary embodiment is the LED package 100 of FIG. 2 except that the filler 162 for increasing the refractive index is included in the second encapsulation portion 160-3. ) Is the same configuration. The rest of the configuration is the same as that of the LED package 100 and therefore the same reference numerals will be given and the description will not be repeated.

When the filler for increasing the refractive index 162 is preferably uniformly dispersed in the second encapsulation portion 160-3, the second encapsulation portion 160-3 may have an increased refractive index than that of the first encapsulation portion 150. The effect is as described above with reference to FIG.

On the other hand, the preferred refractive index increasing filler 162 includes SiO ₂ having a refractive index of 1.45 or more, a transmittance of 80% or more, TiO ₂ having a refractive index of 2.5 or more, and a reflectance of 90% or more, and the smaller the particle size to nano size, the more effective. .

An LED package 100-4 according to a fourth embodiment of the invention is shown in cross section in FIG. 6.

Referring to FIG. 6, the LED package 100-4 of the present embodiment is similar to the LED packages 100 and 100-3 of FIGS. 2 and 5, but has a light diffusing agent 164 in the second encapsulation unit 160-4. ) Is added. The rest of the configuration is the same as that of the LED packages 100 and 100-3, and therefore the same reference numerals will be given and will not be described again.

In the LED package 100-4 of the present embodiment, the finely dispersed light diffusing agent 164 preferably uniformly dispersed in the second encapsulation portion 160-4 is the LED chip 130 or the focus F thereof. Refract the light (L1) arrived at. The light refracted by the light diffusing agent 164 is emitted out of the second encapsulation portion 160-4 at an angle that is wider than the propagation angle as a whole. In this case, as described above with reference to FIG. 2, light generated from the LED chip 130 may be emitted from the LED package 100-4 at a wider angle. In other words, the effect of increasing the aiming angle can be obtained.

Meanwhile, the light diffusing agent 164 may be a polymer, an opal mineral, SiO ₂ , TiO _2, or the like.

Hereinafter, an LED package according to a fifth embodiment of the present invention will be described with reference to FIG. 7.

Referring to FIG. 7, the LED package 100-5 according to the present embodiment includes the LEDs described above in the configuration of the first and second lead frames 110 and 120, the LED chip 130, and the package body 140. Same as the package 100. However, an encapsulation portion 150-5 in which the light diffusing agent 152 is mixed is formed in the cup portion formed around the LED chip 130 by the package body 140, and a dome is formed on an upper surface of the encapsulation portion 150-5. The point where the second encapsulation part 160-5 made of a cover or lens of the form is attached is distinguished. The second encapsulation portion 160-5 is coupled to the first encapsulation portion 150-5 by the adhesive 166, but may be attached by other suitable means.

The light diffusing agent 152 diffuses the light generated by the LED chip 130 and emits it out of the first encapsulation part 150-5, thereby increasing the directing angle of the light. In addition, the second encapsulation portion 160-5 attached to the upper surface of the first encapsulation portion 150-5 further increases the directing angle of the light emitted from the first encapsulation portion 150-5. By such a configuration, the LED package 100-5 may have an increased orientation angle.

Meanwhile, the light diffusing agent 152 may be a polymer, an opal mineral, SiO ₂ , TiO _2, or the like.

Although the technical spirit of the present invention has been described in detail according to the above-described preferred embodiment, it should be noted that the above-described embodiments are for the purpose of description and not of limitation.

In addition, those skilled in the art will understand that various implementations are possible within the scope of the technical idea of the present invention.

1 is a longitudinal sectional view of an LED package according to the prior art.

2 is a longitudinal sectional view of the LED package according to the first embodiment of the present invention.

3 is a view for explaining a directivity angle characteristic of the LED package of FIG.

4 is a longitudinal sectional view of the LED package according to the second embodiment of the present invention.

5 is a longitudinal sectional view of the LED package according to the third embodiment of the present invention.

6 is a longitudinal sectional view of the LED package according to the fourth embodiment of the present invention.

7 is a longitudinal sectional view of the LED package according to the fifth embodiment of the present invention.

<Explanation of symbols of main parts in drawings>

110, 120: lead frame 130: LED chip

140: package body 142: inclined surface

150, 160: sealing part 152, 164: light diffusing agent

162: filler for increasing the refractive index

Claims (7)

A first lead frame and a second lead frame disposed at intervals from each other and made of thermal and electrical conductors; An LED chip electrically connected to the first lead frame and the second lead frame; A package surrounding at least a portion of the first and second lead frames, protruding an extension of the first lead frame and an extension of the second lead frame to an outside, and an inclined inner surface forming a cup around the LED chip; main body; A first encapsulation portion which at least partially fills the cup portion while encapsulating the LED chip; And A second encapsulation part having a refractive index greater than that of the first encapsulation part and disposed in a cup part of the main body at an upper layer of the first encapsulation part, The first lead frame includes a base on which the LED chip is mounted, a connection part inclined upwardly outwardly from the base, and an extension part extending horizontally again from the connection part, The first encapsulation portion and the second encapsulation portion are directed by emitting at least a portion of the light traveling from the LED chip toward the inclined inner surface of the package main body without colliding with the inclined inner surface based on the difference in refractive index. LED package, characterized in that configured to increase the angle. The LED package according to claim 1, wherein the second encapsulation part contains a filler for increasing the refractive index. The LED package according to claim 1 or 2, wherein the second encapsulation portion protrudes beyond an upper end of the package body in a dome shape. The LED package of claim 1, wherein the second encapsulation portion contains a light diffusing agent. The LED package of claim 4, wherein the light diffusing agent is at least one selected from the group consisting of a polymer, an opal mineral, SiO ₂ , and TiO ₂ . The LED package of claim 1, wherein the first encapsulation portion contains a light diffusing agent, and the second encapsulation portion is attached to an upper surface of the first encapsulation portion to protrude beyond an upper end of the package body in a dome shape. . The LED package of claim 6, wherein the light diffusing agent is at least one selected from the group consisting of a polymer, an opal mineral, SiO ₂ , and TiO ₂ .

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