KR100974336B1 - Light emitting diode package - Google Patents

Abstract

The present invention provides a light emitting diode package that can be easily applied to a variety of models by making it possible to easily implement surface light emission by simply adjusting the brightness distribution of the lens unit, and to manufacture a lens unit having a variety of luminance distribution with one mold. It aims to do it. To this end, the present invention is a light-emitting material which covers an inlet portion drawn from the surface and a plate having a reflective surface around the inlet portion, a light emitting diode chip seated on the inlet portion of the plate, and the light emitting diode chip. A light emitting medium including a light emitting medium, the light emitting medium having a curvature on at least a portion of the light emitting medium, and having a first light transmitting portion and a second light transmitting portion through which light emitted from the light emitting diode chip and the light emitting medium passes. The present invention provides a light emitting diode package including a lens unit having a luminance of light transmitted through the first light transmitting unit higher than a luminance of light transmitted through the second light transmitting unit.

Description

Light emitting diode package

The present invention relates to a light emitting diode package, and more particularly, to a light emitting diode package that can implement a local luminance difference.

A light emitting diode is a device that converts electricity into light using characteristics of a compound semiconductor, and has been variously used and developed as a next generation lighting source.

Such light emitting diodes have been recently developed into various displays, and in particular, many researches and developments have been made as backlight units of liquid crystal displays.

In order to use a light emitting diode that is a point light source as a backlight, a plurality of light emitting diodes that are point light sources are arranged on a surface, and point light is diffused and scattered through a diffusion sheet, a prism sheet, or the like on the light emitting diode to make a surface light source. However, in this case, in order to obtain a surface light source having an even surface brightness, the backlight unit is thick because the optical sheets must be disposed at a predetermined height in the light emitting surface of the light emitting diode.

In order to improve this problem, a method of reducing the arrangement interval of light emitting diodes has been sought, but there is a problem of cost increase due to the increase in the number of light emitting diodes per unit area.

In addition, in order to solve the above problems, a technique of applying a side emitting lens to a side emitting light emitting diode has been proposed.

For example, Korean Patent Laid-Open Publication No. 2006-0135207 discloses a light emitting diode lamp that exhibits a maximum luminance in the range of 55 degrees to 80 degrees with respect to the vertical axis by a lens unit having an inclined surface that is lowered from the periphery to the center. .

However, in the case of applying the conventional side emission lenses, it is necessary to design a lens of various types in consideration of the distance between the array of light emitting diodes and the distance from the light emitting source to the optical sheet in order to implement the surface light emitting.

Therefore, when the application to the product requires a large number of molds for forming a lens according to the type of backlight unit model, there is a limit that is difficult to flexibly cope with the model change.

The present invention has been made to solve the above problems, an object of the present invention is to provide a light emitting diode package that can easily implement surface light emission by simply adjusting the brightness distribution of the lens unit.

Another object of the present invention is to provide a light emitting diode package that can be flexibly applied to various models by being able to manufacture a lens unit having various luminance distribution with one mold.

In order to achieve the above object, the present invention includes a plate having an inlet portion drawn from the surface and a reflection surface around the inlet portion, a light emitting diode chip seated on the inlet portion of the plate, and covering the light emitting diode chip, A light emitting medium including a light emitting material and a first light transmitting portion and a second light positioned on the light emitting medium and having a curvature on at least a portion of the light emitting medium, and the light emitted from the light emitting diode chip and the light emitting medium is transmitted; The light emitting diode package includes a lens unit having a transmissive part and a luminance of light transmitted through the first light transmitting part is higher than a luminance of light transmitted through the second light transmitting part.

The first light transmitting part and the second light transmitting part may be provided to have different surface roughnesses.

The second light transmitting part may further include a light absorption filter.

The second light transmitting part may further include a light reflecting part.

The lens part may include a flat part provided to have a flat surface, and the second light transmitting part may include at least a part of the flat part.

The second light transmitting part may be positioned directly on the light emitting diode chip.

The second light transmitting part may be provided as a boundary corresponding to an outer boundary of the reflective surface.

The plate may include a plurality of lead portions and a reflective surface, the light emitting diode chips may be seated on the lead portions, and the light emitting medium may cover the respective light emitting diode chips.

The second light transmitting part may be positioned directly on the light emitting diode chips.

The second light transmitting part may be provided in a number corresponding to the number of the LED chips.

The second light transmitting part may be provided as a boundary corresponding to an outer boundary of the plurality of reflective surfaces, respectively.

The second light transmitting part may be provided as a boundary including outer boundaries of the plurality of reflective surfaces.

According to the present invention as described above, by intentionally lowering the brightness of the predetermined region of the upper portion of the light emitting diode chip through the second light transmitting portion, it is possible to easily achieve a surface light source when a plurality of such light emitting diode packages are arranged.

In addition, various types of lens parts may be formed by using a single mold corresponding to various models without having to vary the mold for molding the lens part according to the type or model of the backlight unit to which the surface light source is applied.

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

1 is a cross-sectional view of a light emitting diode package according to an exemplary embodiment of the present invention.

As shown in FIG. 1, the LED package according to the exemplary embodiment of the present invention has a structure in which the LED chip 30 is mounted on the lead frame 20 and the lens unit 40 is mounted.

The lead frame 20 may include a positive electrode lead and a negative electrode lead, and the mounting portion 24 drawn in a predetermined depth from the surface 22 of the lead frame 20 on a die pad on which the LED chip 30 is seated. It is provided to have, and has a first reflective surface 26 along the edge of the seating portion (24). The first reflecting surface 26 is preferably provided to surround the mounting portion 24 on which the light emitting diode chip 30 is seated. The first reflecting surface 26 reflects light emitted from the light emitting diode chip 30 in the lateral direction upwards. The luminous efficiency is further improved.

The first reflecting surface 26 and the mounting portion 24 as described above may be formed into a cup shape on the die pad by forming the lead frame 20 through etching or a downset mold. However, the present invention is not limited thereto and may be formed in the lead frame 20 by injection using a separate resin or through transfer molding or injection molding.

The light emitting diode chip 30 is bonded to the seating portion 24 with a die adhesive and connected to the surface 22 of the lead frame 20 by a wire 32.

In addition, a first medium 34 is coated on the recess 24 having the groove shape drawn from the surface to cover the LED chip 30.

The first medium 34 includes phosphors, and a mixture of phosphors with a transparent epoxy or silicone resin in a predetermined ratio may be used. The phosphor is excited by only the emission wavelength of the light emitting diode chip 30 to emit light, and may be a silicate-based phosphor or a nitride-based phosphor having high purity to excite and emit a single independent wavelength.

The first medium 34 is not necessarily limited to one containing a phosphor, and a phosphor and / or a pigment of a specific color may be mixed.

The first medium 34 is applied to cover the light emitting diode chip 30 through a transfer molding or dispensing process and is applied to a predetermined thickness.

An edge of the lead frame 20 is further provided with a base 10 which is injection or transfer molded of a thermosetting and / or plastic resin of a highly reflective material, and the second reflective surface 12 on the inner side of the base 10. ) Is formed.

In the above structure, the lens unit 40 is formed on the light emitting diode chip 30 and the first medium 34.

The lens unit 40 is formed of a transparent resin material and formed by transfer molding or injection molding after seating the lead frame 20 assembled as described above in a separate lens mold. The lens unit 40 serves as a second medium that mixes and transmits the light emitted from the first medium 34 and further diffuses the light in the lateral direction.

In the present invention, the lens portion 40 has a first light transmission portion 42 and a second light transmission portion 44 for transmitting the light emitted from the first medium 34. At this time, the luminance of the light transmitted through the first light transmission part 42 is higher than the luminance of the light transmitted through the second light transmission part 44.

That is, as shown in FIG. 1, the first transmission region L1 formed by transmitting light through the first light transmission part 42 is the second transmission region formed by passing light through the second light transmission part 44. It is brighter than L2.

In this case, the second light transmission part 44 is positioned directly above the light emitting diode chip 30, and the outer circumferential boundary thereof is substantially coincident with the outer circumferential boundary of the first reflective surface 26. The second light transmitting portion 44 is formed on the surface of the lens portion 40 by a certain degree of uneven surface 46, that is, the surface roughness of the second light transmitting portion 44 is the first light transmitting portion. It can be realized by making it rougher than the surface roughness of (42). Due to such a high surface roughness in the second light transmitting portion 44, when light emitted from the first medium 34 passes through the second light transmitting portion 44, diffusion in the direction of the first transmission region L1 is prevented. As a result, the second transmission area L2 corresponding to the center area is darker than the first transmission area L1.

By intentionally lowering the luminance of the predetermined region of the upper portion of the light emitting diode chip 30 through the second light transmitting portion 44, the maximum luminance can be obtained at a portion spaced about 70 degrees from the center as shown in FIG. Can have Therefore, the surface light source can be easily achieved by arranging a plurality of such light emitting diode packages.

On the other hand, as described above, obtaining the surface light source exists in various ways due to the arrangement interval of the light emitting diodes, the interval between the light emitting diode light source and the sheet, and the like. That is, in the graph of FIG. 2, whether the lens unit is designed to have the maximum luminance from the center line may vary depending on the type or model of the backlight unit to which the corresponding surface light source is applied.

In this case, the present invention can easily cope with when the model of the backlight unit is changed in this way by adjusting the area of the second light transmitting part 44 or its outer periphery boundary.

That is, as shown in FIG. 1, the desired luminance range can be easily set by setting the outer circumferential boundary of the second light transmitting portion 44 to a range that is spaced from the upper portion of the outer boundary of the first reflecting surface 26 by a predetermined angle α. You can get it.

In addition, when the outer circumference of the second light transmitting portion 44 is changed in this way, a method of manufacturing the same becomes very simple.

That is, as described above, the lens unit 40 is molded with a resin material and is injected by molding the resin material into the mold in a state where the lead frame 20 is seated in the mold. In this case, the second light transmission part 44 may be formed by forming irregularities on the inner surface of the mold, but the model may need to be changed to redesign the outer circumferential boundary of the second light transmission part 44. In this case, the unevenness of the inner surface of the used mold can be removed by polishing and then subjected to sanding again. Therefore, a single mold can be applied even when changing the model.

In another method, the same lens portion 40 without the above-mentioned irregularities is formed into a mold, and then the second light transmitting portion 44 is locally formed on the surface thereof by sanding or the like, so that the same can be achieved even when the model is changed. The mold can be used.

As described above, the present invention enables not only to generate a local luminance difference by changing the outer curvature of the lens but also to easily implement a surface light source for various models by setting the second light transmitting part, which is a low luminance part, on the lens surface.

Meanwhile, in the above-described embodiment, the second light transmitting part 44 is artificially formed as a low luminance part as compared to the first light transmitting part 42. However, the present invention is not limited thereto, and the second light transmitting part 44 is not limited thereto. The difference in relative brightness between the light passing through and the light passing through the first light transmission part 42 is important. That is, the light passing through the first light transmitting part 42 should have a higher luminance than the light passing through the second light transmitting part 44. For this purpose, the light transmittance of the second light transmitting part 44 is the same as in the above-described embodiment. Also, the second light transmitting part 44 may be formed in an internal light reflection type structure so that light incident on the second light transmitting part 44 may be reflected to the other side and eventually extracted to the first light transmitting part 42. In this case, the light passing through the first light transmitting part 42 may have a higher luminance than the light passing through the second light transmitting part 44. This light-reflective structure adjusts the shape of the unevenness formed in the second light transmission part 44 to increase the total reflectance of the light emitted from the light emitting diode chip 30 or to refract the direction of the first transmission area L1. It is applicable by designing so that it becomes large quantity.

3 illustrates another preferred embodiment of the present invention. The surface roughness of the first light transmitting portion 42 is formed by the uneven surface 46 of the first light transmitting portion 42. It is made to be rougher than the surface roughness of (44). At this time, the second light transmitting portion 44 has a structure in which the center portion is led in the direction of the light emitting diode chip 30 so that the center has an inclined surface 45 in which the center is recessed, and the flat portion is flat in the center of the inclined surface 45. Form a face. Due to the structure of the second light transmitting part 44, the light emitted through the first medium 34 toward the second light transmitting part 44 may be reflected at different angles, and thus the light toward the first light transmitting area L1 may also be reflected. This can be induced. As a result, the first transmission area L1 may appear brighter than the second transmission area L2. The second light transmitting portion 44 may polish the surface to better reflect the light. That is, when the second light transmitting part 44 is mirrored through a polishing process, the inclined surface (eg, to switch the light toward the second transparent area L2 to the side surface, that is, the first transparent area L1). 45) can further increase the reflectivity. On the contrary, by forming the uneven surface 46 in the first light transmission part 42, the light of the first transmission area L1 can be further diffused outward. In this case, the left and right peak shapes shown in FIG. 2 may take a rounded shape that spreads laterally rather than having a sharp shape as shown in FIG. 2.

As such, the present invention causes the difference in local surface roughness to occur on the surface of the lens unit so that the luminance of the first transmission region L1 is higher than the luminance of the second transmission region L2, but variously change the luminescence properties at this time. You can.

Figure 4 shows another preferred embodiment of the present invention, the lens portion 40 is to include a flat portion provided so that some surface is flat. That is, the lens portion 40 is to be formed as a curvature surface having one or more curvature radius, the outer surface is to have a flat surface having no curvature in some areas. The flat portion 46 may be positioned directly above the light emitting diode chip 30.

The second light transmitting portion 44 may include at least a portion of the flat portion. In the embodiment according to FIG. 4, the second light transmitting portion 44 and the flat portion coincide with each other. However, the present invention is not necessarily limited thereto, and the area of the second light transmitting part 44 and the area of the flat part do not necessarily have to match.

According to the flat portion, the light has a straightness in a predetermined region, and by arranging the second light transmitting portion 44 in this portion, it is possible to minimize the luminance of the straight region.

Figure 5 shows another preferred embodiment of the present invention.

In the case of the embodiment according to FIG. 5, the second light transmission unit 44 is implemented by attaching a separate light absorption filter 48 to the surface of the lens unit 40.

The light absorption rate of the light absorption filter 48 may be variously changed according to design conditions, and a filter having a light absorption rate of approximately 20 to 80% may be used.

By implementing the second light transmission unit 44 by attaching the light absorption filter 48 to the surface of the lens unit 40 as described above, even if the model is changed as described above, the type and size of the filter can be changed without changing the mold. You can simply respond.

The implementation of the second light transmission unit 44 by the light absorption filter 48 may be applied to all embodiments of the present invention.

On the other hand, instead of the light absorption filter 48, by forming an internal light reflecting film (not shown) in the same position as the light absorption filter 48, the light emitted from the light emitting diode chip 30 as described above is a second The light penetrating portion 44 may be reflected back to the inside to be taken out to the first transmission region L1. The internal light reflecting film at this time is intended to mainly reflect the light emitted from the light emitting diode chip 30.

6 illustrates another preferred embodiment of the present invention, which illustrates a case where one package is implemented using two or more light emitting diode chips.

In this case, the lead frame 20 is formed to have two or more seating portions 24, 24 ′ and first reflecting surfaces 26, 26 ′, and each seating portion 24, 24 ′ emits light. The diode chips 30 and 30 'are seated, and the first medium 34 and 34' are coated to cover the light emitting diode chips 30 and 30 '.

Each LED chip 30 and 30 ′ may be a chip emitting blue light, a chip emitting red light, or a chip emitting green light, or a combination thereof. Of course, the color is not necessarily limited to the red cyan three primary colors, for example, various color combinations that can implement white is applicable.

In addition, each of the first media 34 and 34 'independently coats those excited only at the emission wavelengths of the respective LED chips 30 and 30'.

Each of the LED chips 30 and 30 ′ has independent terminals to be driven independently from each other on the lead frame 30, and the amount of light of each of the LED chips 30 and 30 ′ may be varied by controlling current. have.

Accordingly, the excitation emission wavelength of the phosphor can be converted into independent single wavelength emission to maximize the fluorescent emission efficiency, and light can be controlled through current control of a plurality of independent LED chips 30 and 30 'having different emission wavelengths. By varying the intensity, the desired color can be adjusted.

Even in this structure, the lens unit 40 may be formed in common with each of the LED chips 30 and 30 '. In addition, the second light transmitting portion 46 is also formed on the upper portion of each light emitting diode chip 30, 30 ', and its outer circumferential boundary forms the outer boundary of each of the first reflecting surfaces 26 and 26'. All are formed in the range covered. Therefore, when the plurality of light emitting diode packages having such a structure are arranged, the surface light source can be easily achieved when applied to the white backlight unit.

On the other hand, as shown in FIG. 7, the second light transmitting parts 46 and 46 'may be provided with a number corresponding to the number of the LED chips 30 and 30'. At this time, the outer circumferential boundary of each of the second light transmission parts 46 and 46 ′ may correspond to the outer boundary of each of the first reflecting surfaces 26 and 26 ′. As a result, a desired luminance distribution can be obtained simply.

8 illustrates another preferred embodiment of the present invention, in which the groove 28 is formed along the periphery of the light emitting diode chip 30 in the seating portion 24. According to the groove 28, when the first medium 34 is coated, it is restricted to flow out of the groove 28 to cover the light emitting diode chip 30 with a predetermined thickness.

As such, when the first medium 34 covers the light emitting diode chip 30 with a uniform thickness, a uniform color distribution since the light emitted from the light emitting diode chip 30 passes through the first medium 34 is the same. Can be achieved. The groove 28 for preventing the flow of the first medium 34 may be formed in various shapes as long as it prevents the flow of the first medium 34, and may be provided in the form of a protrusion in addition to the groove. have.

3 to 5 may be applied to the embodiment according to FIGS. 6 to 8 as it is.

As described above, in the exemplary embodiments of the present invention, when the plurality of light emitting diode packages are disposed by effectively lowering the luminance by the second light transmitting unit 44, the surface light source may be effectively formed.

Although the light emitting diode package described above is limited to the lead frame type, the present invention is not necessarily limited thereto, and the present invention can be applied to various types of light emitting diode packages such as flip chip type.

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 scope of the present invention as defined by the following claims It can be understood that

1 is a cross-sectional view of a light emitting diode package according to an embodiment of the present invention;

FIG. 2 is a graph showing the light luminance distribution of the light emitting diode package of FIG.

3 is a cross-sectional view of a light emitting diode package according to another exemplary embodiment of the present invention;

4 is a cross-sectional view of a light emitting diode package according to another preferred embodiment of the present invention;

5 is a cross-sectional view of a light emitting diode package according to another preferred embodiment of the present invention;

6 is a cross-sectional view of a light emitting diode package according to another preferred embodiment of the present invention;

7 is a cross-sectional view of a light emitting diode package according to another preferred embodiment of the present invention;

Figure 8 is a cross-sectional view of a light emitting diode package according to another preferred embodiment of the present invention.

* Brief description of the main parts of the drawing *

10: base 12: second reflecting surface

20: lead frame 24: seating portion

26: first reflecting surface 30: light emitting diode chip

34: first medium 40: lens unit

42: first light transmission unit 44: second light transmission unit

45: slope 46: uneven surface

48: light absorption filter

Claims (12)

A plate having an inlet drawn from the surface and a reflective surface around the inlet; A light emitting diode chip seated on an inlet portion of the plate; A light emitting medium covering the light emitting diode chip and including a light emitting material; And Located above the light emitting medium and provided to have a curvature on at least a portion of the light emitting medium, the first light transmitting portion and the second light transmitting portion through which the light emitted from the light emitting diode chip and the light emitting medium passes, and the first light transmitting portion And a lens unit having a luminance higher than that of the light transmitted through the second light transmitting unit. The method of claim 1, The first light transmitting portion and the second light transmitting portion is a light emitting diode package, characterized in that provided with different surface roughness. The method of claim 1, The second light transmitting unit further comprises a light absorption filter. The method of claim 1, The second light transmitting unit further comprises an internal light reflecting unit for reflecting light emitted from the light emitting diode chip. The method of claim 1, The lens unit includes a flat portion provided with a portion of the flat surface, and the second light transmitting portion comprises at least a portion of the flat portion LED package. The method of claim 1, The second light transmitting portion is a light emitting diode package, characterized in that located directly on the light emitting diode chip. The method of claim 1, The second light transmitting portion is a light emitting diode package, characterized in that provided with a boundary corresponding to the outer boundary of the reflective surface. The method of claim 1, The plate has a plurality of inlets and a reflective surface, the light emitting diode chip is mounted on the inlet respectively, the light emitting medium package, characterized in that covering the respective light emitting diode chip. The method of claim 8, The second light transmitting portion is a light emitting diode package, characterized in that located directly on the light emitting diode chips. The method of claim 8, The second light transmitting unit is a light emitting diode package, characterized in that provided with a number corresponding to the number of the light emitting diode chips. The method of claim 10, The second light transmitting portion is a light emitting diode package, characterized in that provided with a boundary corresponding to each of the outer boundaries of the plurality of reflective surfaces. The method of claim 8, The second light transmitting portion is a light emitting diode package, characterized in that provided with a boundary including an outer boundary of the plurality of reflective surfaces.

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