KR20070094247A - Side-view light emitting diode package having a reflector - Google Patents

Abstract

A side-view light emitting diode package is provided to improve the efficiency of light emitting by reflecting the light emitted from a light emitting diode chip using a reflector. First and second lead terminals(11,13) are spaced apart from each other, and are supported by a package body(15) having an elongated opening(16), through which a light emitting diode chip mounting region and the first and second lead terminals are exposed. Reflectors are formed between the light emitting diode chip mounting region and sidewalls(15W) positioned in a major axis direction of the opening, and have a height lower than that of the sidewall of the opening.

Description

Side light emitting diode package with reflector {SIDE-VIEW LIGHT EMITTING DIODE PACKAGE HAVING A REFLECTOR}

1 is a plan view for explaining a side light emitting diode package according to the prior art.

2 is a perspective view illustrating a side light emitting diode package according to the related art.

3 is a plan view illustrating a side light emitting diode package according to an embodiment of the present invention.

4 is a cross-sectional view taken along the line A-A of FIG.

5 and 6 are a simplified plan view and a perspective view for explaining a side light emitting diode package according to an embodiment of the present invention.

7 are plan views illustrating various shapes of the reflector of the present invention.

8 (a) to (d) are graphs for explaining the spatial distribution of light according to the use of the reflector of the present invention.

The present invention relates to a side-view light emitting diode package, and more particularly, to a side light emitting diode package capable of maximizing light efficiency by providing a reflector inside the package.

In general, a light source system using a light emitting diode chip is formed by mounting a light emitting diode (LED) chip in various types of packages according to the intended use. Side light emitting diode packages are mainly used for backlight illumination for displays because they are disposed on the side of the light guide plate to provide light in parallel to the light guide plate.

1 and 2 are a plan view and a perspective view for explaining a conventional side light emitting diode package.

1 and 2, the side light emitting diode package includes a pair of lead terminals, that is, first and second lead terminals 11 and 13. The first and second lead terminals 11 and 13 are supported by the package body 15. The package body 15 may be formed by insert molding lead terminals.

For convenience of description, the package body 15 may be divided into an upper package body 15a and a lower package body 15b based on the positions of the first and second lead terminals 11 and 13.

The upper package body 15a has an opening 16 exposing the first and second lead terminals 11, 13. The first and second lead terminals 11, 13 are located on the bottom of the opening 16, that is, on the lower package body 15b, and are spaced apart from each other in the opening. In addition, the first and second lead terminals 11 and 13 protrude out of the package main body 15 to be electrically connected to an external power source. The lead terminals 11 and 13 protruding to the outside may have various shapes and may be bent into various shapes. 1 and 2 show lead terminals 11 and 13 that are bent laterally from the lower surface of the package body 15 for surface mounting.

The LED chip 17 is mounted and electrically connected to the first lead terminal 11 in the opening 16, and is electrically connected to the second lead terminal 13 by a bonding wire. The opening 16 may be filled with a light transmitting resin, and phosphors may be contained in the light transmitting resin.

The conventional side light emitting diode package has an elongated opening 16, and forms sidewalls, in particular, sidewalls 15w in the long axis direction, to widen the viewing angle in the long axis direction. Accordingly, a side light emitting diode package suitable for a backlight for a display can be provided, and a side light emitting diode emitting white light by appropriate selection of a light emitting diode chip and phosphor can be provided.

However, the side light emitting diode package according to the related art has a problem in that light emitted from the light emitting diode chip is lowered in luminous intensity due to absorption, scattering, etc. inside the package body, and the light efficiency is low. Therefore, continuous efforts to improve the luminous efficiency of the side light emitting diode package are required.

The technical problem to be achieved by the present invention is to provide a side light emitting diode package that can improve the luminous efficiency.

In order to achieve the above technical problem, the present invention provides a side light emitting diode package having a reflector. The side light emitting diode package includes a first lead terminal and a second lead terminal spaced apart from each other. The package body supports the first and second lead terminals. The package body has an elongated opening that exposes a light emitting diode chip mounting region and the first and second lead terminals. Reflectors are respectively located between the light emitting diode chip mounting region and sidewalls in the long axis direction of the opening. The reflectors have a height lower than the opening sidewalls. Accordingly, light emission efficiency may be improved by reflecting light emitted from the light emitting diode chip using a reflector, and the viewing angle may be adjusted by adjusting the height and inclination angle of the reflectors.

The reflectors may be integrally integrated with the package body. Thus, the package body and the reflectors can be easily formed using a molding technique.

Cross sections of the reflectors may form at least a portion of a circle, ellipse or square frame. This shape allows the emitted light to be symmetrically emitted.

Meanwhile, a light emitting diode chip is mounted in the light emitting diode chip mounting region, and the light emitting diode chip is electrically connected to the first and second lead terminals. The light emitting diode chip may be mounted on the first lead terminal, and a bonding wire may electrically connect the light emitting diode chip to the second lead terminal.

In addition, the opening may be filled with a light transmitting resin, and the light transmitting resin may contain phosphors.

Sidewalls of the package body and inner wall surfaces of the reflectors may have scattering reflection surfaces. The scattering reflecting surface improves luminous efficiency compared to the general mirror reflecting surface.

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.

3 is a plan view illustrating a side light emitting diode package having reflectors 21a and 21b according to an embodiment of the present invention, and FIG. 4 is a cross-sectional view taken along the line A-A of FIG. 3. Here, the reference numeral H denotes the height when the side light emitting diode package is mounted.

3 and 4, the side light emitting diode package includes a pair of lead terminals, that is, first and second lead terminals 11 and 13. The first and second lead terminals 11 and 13 are supported by the package body 15. The package body 15 may be formed by insert molding lead terminals. In addition, the package body 15 may be divided into an upper package body 15a and a lower package body 15b based on the positions of the first and second lead terminals 11 and 13.

The upper package body 15a has an opening 16 exposing the first and second lead terminals 11 and 13, and the LED chip mounting region is exposed by the opening 16. The first and second lead terminals 11 and 13 are located on the bottom of the opening 16, that is, on the lower package body 15b, and are spaced apart from each other in the opening 16. In addition, the first and second lead terminals 11 and 13 protrude out of the package main body 15 to be electrically connected to an external power source. The lead terminals 11 and 13 protruding to the outside may have various shapes and may be bent into various shapes. Here, lead terminals 11 and 13 that are bent to the side from the lower surface of the package body 15 for surface mounting are shown. Since the lead terminals 11 and 13 may be variously bent, the lead terminals 11 and 13 may be applied to other light emitting diode packages, for example, tower light emitting diode packages.

The LED chip 17 is mounted in the LED chip mounting region in the opening 16 and electrically connected to the first and second lead terminals 11 and 13. As illustrated, the light emitting diode chip 17 may be mounted on the first lead terminal 11 and electrically connected to the second lead terminal 13 by the bonding wire 19. Alternatively, the LED chip 17 may be mounted on the lower package body 15b and electrically connected to the first and second lead terminals by bonding wires, respectively.

In addition, the side light emitting diode package according to the present embodiment includes reflectors 21a and 21b. These reflectors 21a and 21b are located between the light emitting diode chip mounting region and the sidewalls 15w in the long axis direction of the opening 16, respectively. The reflectors 21a and 21b have a reflecting surface that is inclined to reflect light emitted from the light emitting diode chip 17 and has a height lower than the sidewalls of the opening 16, for example, the sidewalls 15w in the long axis direction. .

The reflectors 21a and 21b may be formed together while inserting and molding the first and second lead terminals 11 and 13 to form the package body 15. Thus, the reflectors 21a, 21b may be formed of the same plastic as the package body 15, such as polyphthalamide (PPA).

The bonding wire 19 may connect the second lead terminal 13 and the LED chip 17 across the upper portion of the reflector 21a.

FIG. 5 is a simplified plan view of the upper package body 15a for explaining a side light emitting diode package according to an embodiment of the present invention, and FIG. 6 is a perspective view of FIG.

5 and 6, the reflectors 21a and 21b are positioned between the LED chip mounting region and the sidewalls 15w in the long axis direction to surround the LED chip mounting region. That is, the LED chip mounting region is surrounded by the reflectors 21a and 21b and the unidirectional sidewalls.

The reflectors 21a and 21b may be integrally formed with the package body 15. The reflectors 21a and 21b may be spaced apart from each other and connected to the package body 15. As shown, the lower parts of the reflectors 21a21b may be connected to each other, and the upper part may be connected to the upper package body 15a. It may be.

7A to 7C are plan views illustrating the shapes of the reflectors 21a and 21b.

Referring to FIG. 7, the cross-sections of the reflectors 21a and 21b may form at least a portion of an edge of a circle (a), an ellipse (b), or a rectangle (c). For example, when the reflectors 21a and 21b are connected to each other to form a closed curved surface surrounding the LED chip mounting area, the cross sections of the reflectors 21a and 21b form a circle, an ellipse, or a rectangular frame, and the reflector When the fields 21a and 21b are spaced apart from each other and connected to the upper package body 15a, the cross sections of the reflectors 21a and 21b constitute both sides of the circle, ellipse, or rectangular frame.

Referring again to FIG. 4, the opening 16 may be filled with a light transmissive resin 23, such as an epoxy or silicone resin. The translucent resin 23 may contain a phosphor for wavelength converting light emitted from the light emitting diode chip 17. A phosphor for converting light emitted from the light emitting diode chip 17, for example, blue light into yellow light may be contained in the translucent resin 23, and thus a side light emitting diode package may be provided that emits white light.

According to the exemplary embodiments of the present invention, the luminous efficiency may be improved by disposing the reflectors 21a and 21b between the LED chip mounting region and the long axis sidewalls 15w of the opening 16. In addition, the light emitting efficiency can be improved without narrowing the viewing angle by making the heights of the reflectors 21a and 21b be lower than those of the long sidewalls 15w.

Hereinafter, the results of the simulation will be described to compare the light emitting performance of the side light emitting diode package of the prior art and the side light emitting diode package according to the embodiments of the present invention. Here, the side light emitting diode package of the prior art used two types of side light emitting diode package (model name: SWTS907 SWTS905) available from Seoul Semiconductor. The heights H of the SWTS907 (0.6T) and the SWTS905 (0.8T) are 0.6 mm and 0.8 mm, respectively, and the heights of the sidewalls of the upper package body 15a are 0.65 mm and 0.75 mm, respectively. On the other hand, the side light emitting diode package according to the embodiments of the present invention, it is assumed that the reflectors are formed in each of the packages, the height of the reflectors is assumed to be 0.25mm, lower inner diameter is 0.22mm, upper inner diameter is 0.4mm It was.

In addition, the light emitting diode chip used two kinds of light emitting diode chips (model names: XT-24 and XB-24) available from Cree, Inc .. XB-24 is a light emitting diode chip in which a light emitting element is formed on a SiC substrate, and XT-24 is a light emitting diode chip formed by removing a SiC substrate after forming a light emitting element on a SiC substrate. On the other hand, it is assumed that the opening 16 of the side light emitting diode package is filled with epoxy resin.

For the simulation, it is assumed that the refractive index of the epoxy resin (nepoxy) is 1.5, the atmospheric refractive index (nair) is 1.0, the SiC refractive index (nSiC) is 2.55, and the GaN refractive index (nGaN) is 2.5. Data was obtained by tracking the progress path. On the other hand, the package body and the reflectors are formed of PPA, and each exposed face of the light emitting diode package and the inner and outer walls of the reflectors form the mirror reflecting surface or the scattering reflecting surface, and the total luminous flux emitted from the light emitting diode package and Luminance luminance was simulated to obtain data.

Table 1 summarizes the various combinations used in the simulation.

Comparative Example or Example package Light emitting diode chip Reflective surface Example 1 0.6T XT-24 Mirror surface Example 2 0.6T XT-24 Spawning surface Example 3 0.6T XB-24 Mirror surface Example 4 0.6T XB-24 Spawning surface Example 5 0.8T XT-24 Mirror surface Example 6 0.8T XT-24 Spawning surface Example 7 0.8T XB-24 Mirror surface Example 8 0.8T XB-24 Spawning surface

Referring to Table 1, each embodiment has the same package, light emitting diode chip, and reflective surface as the respective comparative examples, and further includes reflectors. The reflectors have the same reflecting surface as the package.

Table 2 summarizes the simulation results for the total luminous flux, the light emission luminance, and the viewing angle of the comparative examples and examples. Here, the total luminous flux was simulated by measuring the luminous flux by condensing on a spherical surface, and the emission luminance was simulated by measuring the LED430 adapter using a luminance meter. On the other hand, the viewing angle is expressed as 1/2 of the total viewing angle.

Total luminous flux (lm) Luminance Luminance (mcd) Viewing angle (2θ1 / 2 °) Comparative example Example % Increase Comparative example Example % Increase Comparative example Example Example 1 3.326 4.147 24.7 16.2 18.6 15.2 68 70 Example 2 4.663 4.709 One 15.2 17.9 17.7 105 95 Example 3 3.294 3.739 11.3 7.9 9.4 18.9 95 95 Example 4 4.268 4.326 1.3 9.7 11.3 16.5 120 110 Example 5 4.178 4.608 10.3 14.9 21.5 44.3 100 80 Example 6 4.792 4.758 -0.7 16.2 18.2 12.3 100 92 Example 7 3.845 4.131 7.4 8.3 11.1 33.7 100 100 Example 8 4.373 4.405 0.7 11.4 13.7 20.2 115 110

Referring to Table 2, the total luminous flux was increased in almost all the embodiments compared to the comparative examples, and the luminous brightness was increased by at least 15% relatively larger than the comparative examples. However, although the viewing angle is generally reduced in the embodiments, the decrease in the viewing angle is relatively small compared to the increase rate of the light emission luminance.

8 is a graph simulating light distribution of Comparative Examples and Examples by the above combination.

Referring to FIGS. 8A to 8D, in the same examples, the spatial distribution of light is not relatively narrow and is generally wider than the comparative examples, and the emission luminance is relatively large at most viewing angles.

In conclusion, by installing the reflectors, the light emission luminance can be further increased in comparison with the narrowing of the viewing angle, and the total light flux can also be significantly increased in the package of the mirror reflection surface.

According to embodiments of the present invention, by adding a reflector to a conventional side light emitting diode package can provide a side light emitting diode package that can improve the luminous efficiency of light emitted to the outside of the package.

Claims (5)

A side light emitting diode package for laterally emitting light emitted from a light emitting diode chip, A first lead terminal and a second lead terminal spaced apart from each other; A package body supporting the first and second lead terminals, the package body having an elongated opening to expose a light emitting diode chip mounting region and the first and second lead terminals; And reflectors positioned between the light emitting diode chip mounting region and sidewalls in the long axis direction of the opening, wherein the reflectors have a height lower than the sidewalls of the opening. The method according to claim 1, And the reflectors are integrally integrated with the package body. The method according to claim 1, And the cross-sections of the reflectors form at least a part of a circle, ellipse, or rectangular frame. The method according to claim 1, Further comprising a light emitting diode chip mounted in the light emitting diode chip mounting area, The light emitting diode chip is a side light emitting diode package electrically connected to the first and second lead terminals. The method according to claim 4, The light emitting diode chip is a side light emitting diode package mounted on the first lead terminal.

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