TW201739841A - Back light unit comprising rare earth metal oxide-added LED package - Google Patents

Abstract

The present disclosure relates to an LED package having enhanced light extraction efficiency by adding a resin for LED package encapsulation and rare earth metal oxides, and a BLU comprising the same.

Description

Backlight unit comprising a rare earth metal oxide-emitting LED package

The present disclosure relates to a backlight unit (hereinafter referred to as BLU) including a light-emitting diode (hereinafter referred to as LED) package to which a rare earth metal oxide is added. In particular, the present disclosure relates to a light emitting diode package having better light extraction efficiency by adding a resin and a rare earth metal oxide for encapsulating a light emitting diode package, and including the light emitting diode package The backlight unit.

Due to the global energy saving trend and the improvement in application quality achieved by the development of compound semiconductor technology, the industrialization of light-emitting diodes has rapidly progressed. A light-emitting diode as a light-emitting device is a semiconductor that transmits and receives signals by converting electric energy into infrared rays or using light of a characteristic of a compound semiconductor, and is applied to household electronic products, remote controllers, electronic screen displays, indicators, various automations. Equipment and similar items.

Light-emitting diodes are also used in displays. As a display, a liquid crystal display (hereinafter referred to as an LCD) is most commonly used, and unlike a self-illuminating active organic light emitting diode (AMOLED), a liquid crystal display does not self-illuminate and thus requires a separate light source, which is called Backlight unit.

The backlight unit plays a role of uniformly projecting light from the rear side of the liquid crystal display unit that does not emit light, so that the display image can be presented. in this way The backlight unit includes a direct-lit backlight unit that uniformly sets the light-emitting diode backlight unit behind the liquid crystal display unit panel, and uses the light-emitting diode backlight unit located on the left and right sides and reflects the same to the light guide plate. An edge-lit backlight unit (having a flat plate that uniformly scatters the light generated by the light-emitting diode to the character on the entire screen), and has become an important issue in terms of slimness The side light type is preferred.

In order to be slimmer, it is necessary to reduce the light guide plate which occupies the largest thickness among the side light types. However, when the light guide plate is reduced, the size of the light emitting diode package is also reduced to cause a reduction in the amount of light. Thus, there is a need for a method of maintaining the amount of light when the light guide plate is reduced. As a result, it is necessary to increase the efficiency (light incident efficiency) of light incident on the light guide plate.

In view of the above description, the present disclosure is directed to providing a backlight unit including a light-emitting diode package in which rare earth metal oxide nanoparticles are added, in order to reduce the amount of light when the light guide plate in the backlight unit is reduced, and to increase the efficiency of irradiation to the light guide plate. For the purpose of (light incident efficiency), the divergence angle (degree of light emission) of the light guide plate irradiated into the light emitting diode package body and the high backlight unit brightness are exhibited by enhancing light efficiency.

One embodiment of the present disclosure provides a backlight unit including a light emitting diode package in which rare earth metal oxide nanoparticles are added.

According to another embodiment of the present disclosure, a light emitting diode package system for adding rare earth metal oxide nano particles is prepared by the following process: including applying a first step of an adhesive on a lead frame; setting a single light a second step process from the diode chip to the lead frame; using a lead frame such as a gold wire a third process step of electrically connecting the light-emitting diode wafers with one of the bonding wires to the lead frame and the light-emitting diode chip; and covering the lead frame with a packaging material of the rare earth metal oxide nano particles A fourth process step of the diode wafer and the bonding wire to protect the LED wafer and the bonding wire and control the angle of beam spread.

According to another embodiment of the present disclosure, the encapsulating material of the rare earth metal oxide nanoparticle is added by adding particles obtained by thermally decomposing the rare earth metal salt and the organic material to, for example, an epoxy resin or a gum base resin. Prepared by forming a resin in one of the light emitting diode encapsulating layers.

According to the disclosure, the rare earth metal oxide nano particles have a n A refractive index within the range of 2.5 and having a particle size ranging from 10 nanometers to 1 micrometer.

100‧‧‧Light Emitter Package

110‧‧‧Substrate

120‧‧‧ lead frame

130‧‧‧Light Diode Wafer

140‧‧‧welding line

150‧‧‧Refl

210‧‧‧Packaging materials

220‧‧‧Rare Earth Metal Oxide Particles

300‧‧‧Lighting diode strips

310‧‧‧Printed circuit board (PCB)

400‧‧‧Backlight unit

410‧‧‧ bottom cover

420‧‧‧reflector

430‧‧‧Light guide

440‧‧‧Several optical films

450‧‧‧Top cover

The subject matter and characteristics of the present disclosure will be clearly shown by the following description of the embodiments and the following figures, wherein: FIG. 1 is a spherical rare earth metal oxide nanoparticle added to a light emitting diode package according to the present disclosure. Scanning electron micrograph; FIG. 2 is a structure of a light emitting diode package using spherical rare earth metal oxide nanoparticles according to the present disclosure; FIG. 3 is a view showing the use of FIG. The light emitting diode package controls the light emitting diode strip structure of the angle of beam spread; and FIG. 4 shows the structure of the backlight unit in which the light emitting diode strip of FIG. 3 is disposed.

In the following, the disclosure will be explained in detail by way of example, but the following examples or examples are merely illustrative and not intended to limit the scope of the disclosure.

According to an embodiment of the present disclosure, a backlight unit is prepared by a light emitting diode package including rare earth metal oxide nanoparticles as shown in FIG.

According to another embodiment of the present disclosure, a rare earth metal oxide nanoparticle-added LED package (100) is used as follows: a lead frame (120) of a ceramic substrate (110) as shown in FIG. a first step process for applying an adhesive; a second step of mounting a single light-emitting diode chip (130) to the lead frame (120); using a lead frame (120) such as a gold wire and a light emitting diode Electrical connection between the polar body wafers (130) is performed by one of the bonding wires (140) connecting the lead frame (120) and the light emitting diode chip (130) to a third process step; and using the rare earth metal oxide nanometer One of the particles (220) encapsulating material (210) covers the lead frame (120), the LED chip (130) and the bonding wire (140), and a fourth process step to protect the LED chip (130) It is manufactured by a process of bonding wires (140) and controlling an angle of beam spread.

According to another embodiment of the present disclosure, the encapsulating material (210) to which the rare earth metal oxide nanoparticles (220) is added is obtained by adding particles obtained by thermally decomposing rare earth metal salts and organic materials to, for example, an epoxy resin. Or a silicone resin can be prepared by forming a polymer resin of one of the light emitting diode encapsulating layers. Can be selected from phenol-based resin, acrylic-based resin, polystyrene resin, polyurethane resin, benzoguanamine resin and epoxy resin and silicone resin. Type as a polymer resin.

The rare earth metal oxide nanoparticles according to the present disclosure are as follows: [Chemical Formula 1]: M _a (OH) _b (CO ₃ ) _c O _d

Wherein M is lanthanum, cerium, lanthanum, aluminum, lanthanum, gallium, zinc, vanadium, zirconium, calcium, lanthanum, cerium, tin, manganese, lanthanum, or cerium, and a is 1 or 2, b is 0 to 2, c It is 0 to 3, and d is 0 to 3.

However, b and c are not zero at the same time.

According to the present disclosure, the rare earth metal oxide nanoparticles comprise at least one or more rare earth metals, and the particles preferably have 1.5 n One of the refractive indices in the range of 2.5, and the size of the particles is preferably set in the range of 10 nm to 1 μm.

With respect to the content of the rare earth metal oxide nanoparticles, the content is preferably about 2% by weight to 20% by weight based on the total of the encapsulating material. In the backlight unit including the light-emitting diode package to which the rare earth metal oxide is added, the relative speeds of the X-direction and Y-direction light of the divergence angle of the light-emitting diode blue wafer in the following embodiments and comparative examples ( The lumens and the relative backlight unit luminance are significantly deteriorated, so rare earth metal oxides other than the above content range are not preferable.

In another embodiment of the present disclosure, the powder is prepared by immersing an alkali metal salt, a divalent metal salt, or a combination thereof with a desired rare earth metal salt.

In the rare earth metal oxide nanoparticles of Chemical Formula 1, the refractive index of such particles is preferably 1.5. n 2.5, and when the refractive index is lower than 1.5 or higher than 2.5, the effect of increasing the light extraction efficiency may not be obtained. This is due to the fact that conventional tantalum encapsulating materials have a refractive index of about 1.5, while gallium nitride wafers have a refractive index of about 2.4. Further, the size of the particles is preferably set to be in the range of 10 nm to 1 μm. However, when the particle size is outside the foregoing range, the light extraction efficiency may be reduced. Further, although it may vary somewhat depending on the wavelength or particle type, an optimum range of light extraction efficiency according to particle size is exhibited, and thus the range of particle size may be a very important condition regarding light extraction efficiency. Further description thereof can be understood by referring to the following examples and test examples.

According to an embodiment of the present disclosure, FIG. 3 illustrates a light-emitting diode strip (300) that controls a divergence angle, and the light-emitting diode strip includes a printed circuit board (hereinafter referred to as PCB, 310) and is mounted. The plurality of light emitting diode packages (100) are used as the light emitting diode source on the upper surface. According to Fig. 3, the LED package (100) is shown mounted on the upper surface of the printed circuit board in accordance with the shape of the light-emitting surface, but may be mounted on the side when needed.

As shown in Fig. 4, a structure of a backlight unit equipped with a light-emitting diode strip for controlling a divergence angle is shown. According to FIG. 4, the backlight unit used in the present disclosure is illustrated as a sidelight type backlight unit, and includes a light guide plate (430) and one of the light emitting diode strips on the side of the light guide plate (430). (300). In Fig. 4, the light emitting diode strips are provided only on one side of the light guide plate (430), however, the light emitting diode strips may be provided on both sides as needed. At the bottom of the light guide plate (430), a bottom cover or molded frame member (410) and a reflective plate or sheet (420) which is an optical additional material may be further provided. The light-emitting diode strip used in the present embodiment can be understood to have a similar structure to the light-emitting diode strip (300) of FIG. In other words The LED strip (300) includes a printed circuit board (310) and a plurality of light emitting diode light sources mounted on the top surface of the board, and uses the foregoing LED package (100) as a light source. Diode source.

Above the light guide plate (430), a plurality of optical sheets or diffusion and fins (440) and a top cover or protective sheet (450) are formed. In other words, the object that emits exactly in the backlight unit is, for example, a cold cathode fluorescent lamp (CCFL) of a fluorescent lamp, and a reflecting plate that reduces light loss by reflecting light that escapes to the bottom when the light is emitted from the lamp. Or a sheet (420) is disposed on the lower layer and located on the upper layer of the luminaire, and the light guide plate (430) that receives the light and uniformly distributes the light to the entire area according to the screen size is located on the upper layer thereof, and is again scattered by self-guided A plurality of optical sheets or diffusion sheets (440) that uniformly diffuse light to the entire surface of the light guide plate (430) on the surface of the light plate (430) are disposed on the upper layer thereof. The light uniformly diffused according to the panel size as described above becomes a light of clear brightness while penetrating the optical sheet or the cymbal (440). The backlight unit is completed when the molded frame member is coupled to an inverter for operating a driver mounted on the backlight unit of the backlight unit stacked upside down in an upside down manner.

In the following, the disclosure will be described with reference to the embodiments, however, these embodiments are intended to illustrate the invention, and are not intended to limit the invention.

Example

Example 1:

After dissolving 2 g of Yttrium nitrate hydrate and 40 g of urea in 100 ml of distilled water, it was mixed for 30 minutes and thoroughly stirred. After stirring, the pH was adjusted to 5.5-5.6 by means of a base of nitric acid and ammonium hydroxide. After heating and stirring the mixture at 90 ° C for 1 hour, the mixture was filtered and washed three times with distilled water. The washed Y(OH)CO ₃ particles were dried in an oven at 70 ° C for 3 hours to prepare Y(OH)CO ₃ particles having a size of 500 nm. After adding Y(OH)CO ₃ particles (98% by weight of crepe-based resin: 2% by weight of Y(OH)CO ₃ ) to the phthalocyanine-based resin (OE 6631A and OE 6631B mixed in a ratio of 1:2) The obtained mixture was homogenized by placing it in a homogenizer to prepare a package composition.

Example 2:

After dissolving 2 g of Yttrium nitrate hydrate and 40 g of urea in 100 ml of distilled water, it was mixed for 30 minutes and thoroughly stirred. After stirring, the pH was adjusted to 5.5-5.6 by means of a base of nitric acid and ammonium hydroxide. After heating and stirring the mixture at 90 ° C for 1 hour, the mixture was filtered and washed three times with distilled water. The washed Y(OH)CO ₃ particles were dried in an oven at 70 ° C for 3 hours to prepare Y(OH)CO ₃ particles having a size of 500 nm. After adding Y(OH)CO ₃ particles (96% by weight of crepe-based resin: 4% by weight of Y(OH)CO ₃ ) to the phthalocyanine-based resin (OE 6631A and OE 6631B mixed in a ratio of 1:2) The obtained mixture was homogenized by placing it in a homogenizer to prepare a package composition.

Example 3:

After dissolving 2 g of Yttrium nitrate hydrate and 40 g of urea in 100 ml of distilled water, it was mixed for 30 minutes and thoroughly stirred. After stirring, the pH was adjusted to 5.5-5.6 by means of a base of nitric acid and ammonium hydroxide. After heating and stirring the mixture at 90 ° C for 1 hour, the mixture was filtered and washed three times with distilled water. The washed Y(OH)CO ₃ particles were dried in an oven at 70 ° C for 3 hours to prepare Y(OH)CO ₃ particles having a size of 500 nm. After adding Y(OH)CO ₃ particles (95% by weight of phthalocyanine resin: 5 weight percent of Y(OH)CO ₃ ) to the phthalocyanine-based resin (OE 6631A and OE 6631B mixed in a ratio of 1:2) The obtained mixture was homogenized by placing it in a homogenizer to prepare a package composition.

Example 4:

After dissolving 2 g of Yttrium nitrate hydrate and 40 g of urea in 100 ml of distilled water, it was mixed for 30 minutes and thoroughly stirred. After stirring, the pH was adjusted to 5.5-5.6 by means of a base of nitric acid and ammonium hydroxide. After heating and stirring the mixture at 90 ° C for 1 hour, the mixture was filtered and washed three times with distilled water. The washed Y(OH)CO ₃ particles were dried in an oven at 70 ° C for 3 hours to prepare Y(OH)CO ₃ particles having a size of 500 nm. After adding Y(OH)CO ₃ particles (90% by weight of crepe-based resin: 10% by weight of Y(OH)CO ₃ ) to the phthalocyanine-based resin (OE 6631A and OE 6631B mixed in a ratio of 1:2) The obtained mixture was homogenized by placing it in a homogenizer to prepare a package composition.

Example 5:

After dissolving 2 g of Yttrium nitrate hydrate and 40 g of urea in 100 ml of distilled water, it was mixed for 30 minutes and thoroughly stirred. After stirring, the pH was adjusted to 5.5-5.6 by means of a base of nitric acid and ammonium hydroxide. After heating and stirring the mixture at 90 ° C for 1 hour, the mixture was filtered and washed three times with distilled water. The washed Y(OH)CO ₃ particles were dried in an oven at 70 ° C for 3 hours to prepare Y(OH)CO ₃ particles having a size of 500 nm. After adding Y(OH)CO ₃ particles (80% by weight of crepe-based resin: 20% by weight of Y(OH)CO ₃ ) to the phthalocyanine-based resin (OE 6631A and OE 6631B mixed in a ratio of 1:2) The obtained mixture was homogenized by placing it in a homogenizer to prepare a package composition.

Comparative example

A package composition was prepared as in Experimental Example 1, except that the rare earth metal oxide nanoparticles were not added, and the silicone resin (OE 6631A and OE 6631B mixed in a ratio of 1:2) was placed in a homogenizer to be homogenized. .

The package compositions of Examples 1-5 and Comparative Examples were placed in a light-emitting diode package having a blue light-emitting diode (wavelength of 450 nm) wafer, and the brightness was measured. In the light-emitting diode package used, the light-emitting diode chip is bonded to the lead frame as a light-emitting source by wafer bonding. The light-emitting diode wafer and the lead frame are electrically joined by metal wire bonding, and then molded by a package containing a silicone resin which is a transparent packaging material and includes inorganic nano particles dispersed therein. It is shown in Table 1 below that the present invention adds the 500 nm to 0%, 2%, 4%, 5%, 10% and 20% of the total packaging material in the backlight unit including the light emitting diode package. The measurement result of the blue light-emitting diode wafer, the divergence angle in the X direction and the Y direction, the relative speed of light (lumen), and the brightness of the associated backlight unit after the rare earth metal oxide nanoparticle.

The backlight unit including the light-emitting diode package including the rare earth metal oxide spherical particles of the present disclosure can control the divergence angle, and an increase in the light incident intensity can be expected.

In other words, the divergence angle can be obtained by coating the rare earth metal oxide spherical particles, and the light incidence efficiency is the relative value of the light from the light guide plate compared to the light from the light emitting diode strip, and is usually irradiated to The light rays located in the light guide plate of the light-emitting diode strip have a value other than 100%. This is due to the difference in the gap between the LED strip and the light guide plate, the difference in refractive index, the angle of divergence of the incident light to the light guide plate, or the like. It can be confirmed that in the present disclosure, the light incident efficiency is increased by about 1% by reducing the divergence angle by 10 degrees from 120 degrees to 110 degrees.

In summary, the disclosure has been explained with reference to the embodiments. However, it is to be understood that a person skilled in the art can variously modify and change the disclosure without departing from the scope of the present invention.

Claims (5)

A backlight unit comprising: a light emitting diode package coated with a packaging material, wherein the packaging material is added with a total of 2% to 20% by weight of the rare earth metal of 10 nm to 1 μm relative to the packaging material Oxide nanoparticles. The backlight unit according to claim 1, wherein the encapsulating material of the rare earth metal oxide nanoparticle is added to the epoxy resin by adding particles obtained by thermally decomposing the rare earth metal salt and the organic material or The crepe-based resin can be prepared by forming a resin of one of the light-emitting diode encapsulating layers. The backlight unit according to claim 1, wherein the rare earth metal oxide nanoparticle has a composition of the following Chemical Formula 1: [Chemical Formula 1]: M _a (OH) _b (CO ₃ ) _c O _d wherein M Is 钪, 钇, 镧, aluminum, lanthanum, gallium, zinc, vanadium, zirconium, calcium, lanthanum, cerium, tin, manganese, lanthanum, or cerium, and a is 1 or 2, b is 0 or 2, c is 0. To 3, and d is 0 to 3, however b is not the same as c. The backlight unit of claim 1, wherein the rare earth metal oxide nanoparticle has a value of 1.5 n One of the refractive indices in the range of 2.5. A manufacturing method of a backlight unit comprising a light-emitting diode package, wherein the light-emitting diode package system is prepared by the following process: applying a first step of an adhesive on a lead frame; setting a single light-emitting diode a second step process of the polar body wafer to the lead frame; electrically connecting the lead frame and the one of the light emitting diode chip by using a bonding wire a three-process process; and a fourth process step of covering the lead frame, the light-emitting diode wafer, and the bonding wire with a packaging material, wherein the packaging material adds 2 weight percent to 20 weights relative to the packaging material A percentage of 10 nm to 1 micron particle size rare earth metal oxide nanoparticles to protect the LED wafer from the bond wire and control a divergence angle.