KR20090132916A - Light emitting device - Google Patents

Abstract

PURPOSE: A light emitting device is provided to improve luminous intensity by forming a white light emitting unit including a blue light emitting chip and a yellow fluorescent material. CONSTITUTION: First to third lead terminals(210-230) are electrically separated. First to third light emitting chips(310-330) are mounted on the chip mounting surfaces of the first to third lead terminals. A cup shaped groove part is formed in a fourth lead terminal(240). The white light emitting unit is formed in the groove part of the fourth lead terminal. The white light emitting unit includes an additional light emitting chip and the fluorescent material. The additional light emitting chip is mounted on the chip mounting surface of the fourth lead terminal. The fluorescent material implements the white light through the wavelength conversion of the light generated from the additional light emitting chip.

Description

Light emitting device {LIGHT EMITTING DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device, and more particularly, to a light emitting device for packaging white light emitting chips that generate monochromatic light to generate white light.

In general, light emitting diodes (LEDs) have many advantages of high luminous efficiency, long life, low power consumption, and eco-friendliness, and thus, the technical field using them is increasing.

Such a light emitting diode is usually manufactured in a package structure in which a light emitting chip is mounted, and is configured to perform a light emitting operation by receiving a current from the outside. To this end, the light emitting diode includes a lead frame for applying a current to the light emitting chip, and a housing for supporting the lead frame. In addition, the light emitting diode may further include a light transmissive molding part formed in an opening formed in the housing to expose the light emitting chip to protect the light emitting chip from the outside.

Recently, white light emitting diodes have been introduced in addition to single color components, for example, red, green or blue light emitting diodes. In addition, the development of a product that implements a full color and white by producing a plurality of light emitting chips in one package is in progress.

As a method of realizing full color and white with one light emitting diode, there are a first method using red, green, and blue light emitting chips, and a second method using red, green, blue, and yellow light emitting chips.

However, in the first method of realizing each color by driving red, green, and blue light emitting chips separately, and driving white light emitting chips simultaneously, white light intensity is significantly lower than that of color light. In addition, in the second method of implementing each color by driving red, green, blue, and yellow light emitting chips separately and driving white light by simultaneously driving four light emitting chips, the light intensity of the yellow light emitting chip is improved compared to the first method. Due to this addition, there is a problem in that variables of driving conditions for adjusting white balance are increased.

Accordingly, the present invention has been made in view of such a problem, and the present invention provides a light emitting device capable of realizing full color and improving white brightness while using red, green, and blue light emitting chips.

A light emitting device according to an aspect of the present invention includes a plurality of lead terminals, a plurality of light emitting chips, at least one fourth lead terminal, a white light emitting unit, and at least one fifth lead terminal. The plurality of lead terminals are electrically separated from each other, and the chip mounting surfaces are formed to be positioned on a first plane having the same plane. The plurality of light emitting chips are mounted on chip mounting surfaces of the plurality of lead terminals, respectively. The fourth lead terminal is provided with a cup-shaped groove so that the chip mounting surface is positioned on a second plane lower than the first plane. The white light emitting portion is formed in the groove portion of the fourth lead terminal to generate white light. The fifth lead terminal is supplied with power having a polarity opposite to the plurality of lead terminals and the fourth lead terminal.

The white light emitting part is filled in the groove to cover the additional light emitting chip and the additional light emitting chip mounted on the chip mounting surface of the fourth lead terminal, and to implement white light through wavelength conversion of light generated by the additional light emitting chip. It may include a first molding portion including a phosphor. For example, the additional light emitting chip may include a blue light emitting chip, and the phosphor may include a yellow phosphor.

One fourth lead terminal and one white light emitting unit may be formed in each package, or two may be formed in each package.

The plurality of lead terminals may include first, second and third lead terminals. In addition, the plurality of light emitting chips may include red, green, and blue light emitting chips mounted on the first, second, and third lead terminals, respectively.

The light emitting device may further include a conductive wire electrically connecting the red, green, blue, and additional light emitting chips to the fifth lead terminal. The light emitting device may further include a housing fixing the first to fifth lead terminals and having an opening for exposing the red, green, blue, and additional light emitting chips. In this case, some of the first to fifth lead terminals may protrude outwardly of the housing and have a structure that is bent at least once. The light emitting device may further include a second molding part filled in the opening of the housing and formed by transparent repair. The light emitting device may further include a lens part formed on the housing to cover the opening.

According to such a light emitting device, by forming a white light emitting part including a blue light emitting chip and a yellow phosphor in addition to the red, green and blue light emitting chips, the brightness of white light can be improved. In addition, the white light emitting portion can be easily formed by forming the white light emitting portion in the groove formed in the lead terminal, and the white light emitting portion is located below the red, green and blue light emitting chips, and is generated by the red, green and blue light emitting chips. Characteristic distortion of the white light can be prevented.

The above-described features and effects of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, and thus, those skilled in the art to which the present invention pertains may easily implement the technical idea of the present invention. Could be.

As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "having" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described in the specification, and that one or more other features It should be understood that it does not exclude in advance the possibility of the presence or addition of numbers, steps, actions, components, parts or combinations thereof.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

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

1 is a plan view illustrating a light emitting device according to an exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line II ′ of FIG. 1.

1 and 2, a light emitting device 100 according to an embodiment of the present invention includes a lead frame 200 for supplying power, a plurality of light emitting chips 310 for implementing full color or white light. 320, 330, and a white light emitting unit 400 for improving the brightness of white light.

The lead frame 200 supports the light emitting chips, and receives power from the outside to supply the light emitting chips to the light emitting chips. For example, the lead frame 200 may be formed of a metal including copper or aluminum having excellent electrical conductivity.

The lead frame 200 may include a plurality of lead terminals electrically separated from each other. For example, the lead frame 200 may include a first lead terminal 210, a second lead terminal 220, and a third lead terminal 230 electrically separated from each other. The first lead terminal 210, the second lead terminal 220, and the third lead terminal 230 have a chip mounting surface on which the red light emitting chip 310, the green light emitting chip 320, and the blue light emitting chip 330 are mounted. Are formed to be located on the first plane P1 which is coplanar.

The lead frame 200 further includes a fourth lead terminal 240 electrically separated from the first, second and third lead terminals 210, 220, and 230. The fourth lead terminal 240 is provided with a cup-shaped groove 242 such that the chip mounting surface is positioned on the second plane P2 lower than the first plane P1. The groove part 242 may be formed in various shapes, for example, circular, elliptical, polygonal, or the like.

The lead frame 200 further includes at least one fifth lead terminal 250 electrically separated from the first, second, third, and fourth lead terminals 210, 220, 230, and 240. A light emitting chip is not substantially mounted on the fifth lead terminal 250, and a power having a polarity opposite to that of the power applied to the first, second, third, and fourth lead terminals 210, 220, 230, and 240 is external. Is applied from.

The first, second, third, fourth, and fifth lead terminals 210, 220, 230, 240, and 250 may increase rigidity of the light emitting device 100 and facilitate molding with the housing 600. It may be formed in a structure bent at least once. For example, the first, second, third, fourth, and fifth lead terminals 210, 220, 230, 240, and 250 may be bent twice to form a "-" shape. The first, second, third, fourth, and fifth lead terminals 210, 220, 230, 240, and 250 may be electrically connected to an external device such as a printed circuit board (PCB) to receive power from the outside. Can be. Thus, at least a portion of each of the first, second, third, fourth and fifth lead terminals 210, 220, 230, 240, 250 may protrude from the housing 600 for electrical connection with an external device. It is formed to be bent at least once. On the other hand, the shape and arrangement of the first, second, third, fourth and fifth lead terminals 210, 220, 230, 240, 250 are not limited to those shown in the figure, It can be changed in various ways.

The plurality of light emitting chips 310, 320, and 330 may include a red light emitting chip 310, a green light emitting chip 320, and a blue light emitting chip 330. The red light emitting chip 310, the green light emitting chip 320, and the blue light emitting chip 330 are respectively disposed on the chip mounting surfaces of the first lead terminal 210, the second lead terminal 220, and the third lead terminal 230. It is mounted. For example, the lower surfaces of the red light emitting chip 310, the green light emitting chip 320, and the blue light emitting chip 330 may be formed of a first lead terminal 210 and a second lead terminal 220 through silver paste. ) And the third lead terminal 230 may be electrically connected to each other. The red light emitting chip 310, the green light emitting chip 320, and the blue light emitting chip 330 generate light in the red wavelength band, the green wavelength band, and the blue wavelength band, respectively, in response to the power applied through the lead frame 200.

The white light emitting unit 400 is formed in the groove 242 of the fourth lead terminal 240 to generate white light. The white light emitting unit 400 may include the additional light emitting chip 410 mounted on the chip mounting surface of the fourth lead terminal 240 and the first molding part 420 filled in the groove 242 to cover the additional light emitting chip 410. ).

The additional light emitting chip 410 is formed of, for example, a blue light emitting chip that generates light in a blue wavelength band. In addition, the first molding part 420 may include a phosphor for implementing white light through wavelength conversion of light generated from the additional light emitting chip 410. The phosphor is formed of, for example, a yellow phosphor. Therefore, the white light emitting unit 400 may implement white light through mixing blue light generated by the additional light emitting chip 410 and light converted by wavelengths. The first molding part 420 including the phosphor is formed in the groove part 242 by, for example, a doting method.

Meanwhile, in addition to using a blue light emitting chip and a yellow phosphor, the white light emitting unit 400 may be formed of a combination of various types of light emitting chips and phosphors that can realize white color.

The light emitting device 100 may further include conductive wires 500 that electrically connect the red, green, blue, and additional light emitting chips 310, 320, 330, and 410 and the fifth lead terminal 250, respectively. . The red, green, blue, and additional light emitting chips 310, 320, 330, and 410 are commonly connected to the fifth lead terminal 250 through the conductive wires 500. Accordingly, the red, green, blue, and additional light emitting chips 310, 320, 330, and 410 may include first, second, third, and fourth lead terminals 210, 220, 230, 240, and fifth lead terminals 250. Emits light in response to power applied to both sides through

The light emitting device 100 includes a housing 600 which fixes the lead frame 200. The housing 600 may be formed by, for example, molding molding using a resin such as polyphthalamide (PPA). The housing 600 has an opening 610 for exposing the red, green, blue, and additional light emitting chips 310, 320, 330, and 410 mounted on the lead frame 200. The opening 610 formed in the housing 300 may be formed to have a substantially circular shape when viewed in plan view. In addition, the inner wall of the housing 600 in which the opening 610 is formed may be formed to be inclined at a predetermined slope in order to increase the reflectance of the light and to improve the luminous efficiency.

The light emitting device 100 may be formed in the opening 610 of the housing 600 to cover the red, green, and blue light emitting chips 310, 320, and 330, the white light emitting unit 400, and the conductive wire 500. The second molding unit 700 may further include. The second molding part 700 is to protect the red, green, and blue light emitting chips 310, 320, and 330, the white light emitting part 400, and the conductive wire 500. For example, the transparent epoxy or silicon It may be formed of a resin. The surface of the second molding part 700 may be formed in various shapes such as a flat plate shape, an optical lens shape, and a shape in which predetermined irregularities are formed.

According to the light emitting device 100, light of various colors may be generated by independently driving the red, green, and blue light emitting chips 310, 320, and 330 disposed on the same plane. For example, only the red light emitting chip 310 may be driven to generate red light, only the green light emitting chip 320 may be driven to generate green light, and only the blue light emitting chip 330 may be driven to generate blue light. have. Further, yellow light may be generated by driving the red and green light emitting chips 310 and 320, and pink light may be generated by driving the red and blue light emitting chips 310 and 330, and green and blue light emitting chips ( The sky blue light may be generated by driving the 320 and 330. In addition, the red, green, and blue light emitting chips 310, 320, and 330 may be simultaneously driven to generate white light. Meanwhile, when the red, green, and blue light emitting chips 310, 320, and 330 are simultaneously driven to generate white light, and the additional light emitting chip 410 made of the blue light emitting chips is driven, the red, green, and blue light emitting chips ( Compared to the case of using only 310, 320, and 330, the brightness of white light can be improved by about 75% to 100%, and the brightness of white light is about 40% even when using red, green, blue, and yellow light emitting chips. ~ 60% improvement. In this case, the white light emitting unit 400 including the additional light emitting chip 410 and the first molding unit 420 is located below the red, green, and blue light emitting chips 310, 320, and 330. The white light generated by the blue light emitting chips 310, 320, and 330 is not influenced, thereby preventing the distortion of the characteristic of the white light, and contributing only to improving the brightness of the white light. In addition, by forming the groove 242 in the fourth lead terminal 240 and the white light emitting part 400 therein, the white light emitting part 400 can be easily formed.

3 is a plan view illustrating a light emitting device according to another exemplary embodiment of the present invention, and FIG. 4 is a cross-sectional view taken along line II-II ′ of FIG. 3.

3 and 4, a light emitting device 800 according to another exemplary embodiment of the present invention includes a first lead terminal 810, a second lead terminal 820, and a chip mounting surface positioned on the same plane. A third lead terminal 830 and red, green, and blue light emitting chips 310, 320, and 330 mounted on the chip mounting surfaces of the first, second, and third lead terminals 810, 820, and 830, respectively. do. In addition, the light emitting device 800 includes two fourths in which the cup-shaped grooves 842 are formed such that the chip mounting surface is positioned on a plane lower than the first, second, and third lead terminals 810, 820, and 830. The lead terminals 840 and two white light emitting parts 400 are formed in the groove 842 of the fourth lead terminal 840 to generate white light. In addition, the light emitting device 800 includes a fifth lead terminal 850 commonly connected to the light emitting chips through the conductive wires 500. In the present exemplary embodiment, except that the fourth lead terminals 840 and the white light emitting units 400 are formed two by one, they have almost the same characteristics as those shown in FIGS. 1 and 2, and thus have the same characteristics. Detailed description of the elements will be omitted.

As such, when the two white light emitting units 400 are formed in the light emitting device 800, the luminance of the white light is about 150% to about 300%, compared to the case where only the red, green, and blue light emitting chips 310, 320, and 330 are used. You can improve it by about 200%.

On the other hand, if necessary, by forming three or more white light emitting parts in the light emitting device, the brightness of white light can be further improved.

5 is a cross-sectional view illustrating a light emitting device according to still another embodiment of the present invention.

Referring to FIG. 5, the light emitting device 900 may further include a lens unit 910 formed to cover the opening 610 on an upper portion of the housing 600 through which light is emitted.

The lens unit 910 is formed to adjust the directivity angle of the light emitted from the light emitting device 900 and may be manufactured in various shapes according to the required directivity angle characteristics. For example, the lens unit 910 may be formed in the shape of a convex lens, as shown in FIG. 5, to implement the top emission light emitting device. At this time, the curvature of the lens is determined according to the required orientation angle.

On the other hand, the rest of the configuration except for the lens unit 910 is the same as the embodiments shown in Figures 1 to 4, detailed description of the same components will be omitted.

In the detailed description of the present invention described above with reference to the preferred embodiments of the present invention, those skilled in the art or those skilled in the art having ordinary skill in the art will be described in the claims to be described later It will be understood that various modifications and variations can be made in the present invention without departing from the scope of the present invention.

1 is a plan view showing a light emitting device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line II ′ of FIG. 1.

3 is a plan view illustrating a light emitting device according to another embodiment of the present invention.

4 is a cross-sectional view taken along the line II-II 'of FIG. 3.

5 is a cross-sectional view illustrating a light emitting device according to still another embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: light emitting device 200: lead frame

210: first lead terminal 220: second lead terminal

230: third lead terminal 240: fourth lead terminal

242: groove 250: fifth lead terminal

310: red light emitting chip 320: green light emitting chip

330 blue light emitting chip 400 white light emitting part

410: additional light emitting chip 420: first molding part

500: conductive wire 600: housing

700: second molding part 910: lens part

Claims (10)

A plurality of lead terminals electrically separated from each other and formed such that the chip mounting surface is positioned on a first plane that is coplanar; A plurality of light emitting chips each mounted on a chip mounting surface of the lead terminals; At least one fourth lead terminal in which a cup-shaped groove is formed such that a chip mounting surface is positioned on a second plane lower than the first plane; A white light emitting part formed in the groove part of the fourth lead terminal to generate white light; And And at least one fifth lead terminal to which power of opposite polarity is applied to the plurality of lead terminals and the fourth lead terminal. The method of claim 1, wherein the white light emitting portion An additional light emitting chip mounted on a chip mounting surface of the fourth lead terminal; And And a first molding part filled in the groove part to cover the additional light emitting chip, the first molding part including a phosphor for implementing white light through wavelength conversion of light generated by the additional light emitting chip. The method of claim 2, Wherein the additional light emitting chip comprises a blue light emitting chip. The method of claim 3, The phosphor includes a yellow phosphor. The method of claim 2, And two fourth lead terminals and two white light emitting units. The method of claim 2, The plurality of lead terminals includes first, second and third lead terminals, Wherein the plurality of light emitting chips comprise red, green, and blue light emitting chips mounted on the first, second, and third lead terminals, respectively. The method of claim 6, And a conductive wire electrically connecting the red, green, blue, and additional light emitting chips to the fifth lead terminal. The method of claim 6, wherein the light emitting device Fixing the first to fifth lead terminal, and further comprising a housing formed with an opening for exposing the red, green, blue and additional light emitting chip, A portion of the first to fifth lead terminal protruding to the outside of the housing has a structure bent at least once. The method of claim 8, And a second molding part filled in the opening of the housing and formed by transparent repair. The method of claim 8, And a lens unit formed on the housing to cover the opening.

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