KR200433111Y1 - The apparatus of led blu - Google Patents

Abstract

The present invention stacks LED chips on the top of a printed circuit board (PCB), designs and applies a transfer mold and various kinds of PCB boards, and mounts and packages the PCB boards through wire bonds. Regarding the LED backlight device which reduces the material cost and the case material by forming a,

Its configuration consists of a thin plate on which electrical components such as integrated circuits, resistors or switches are soldered to form a printed circuit board (PCB) in which a predetermined control circuit is formed, and is arranged in a matrix form on an upper surface of the printed circuit board (PCB). And a plurality of LED chips whose light emission and input current values are controlled by the control circuit, disposed on an upper surface of the printed circuit board, and formed to penetrate back and forth at positions corresponding to the respective LED chips. A mold having a through hole formed thereon, the pad being formed on an upper surface of the printed circuit board and formed of an anode and a cathode, and formed on an LED chip and wire bonding, and formed on a bottom surface of the printed circuit board. External electrode terminal electrically connected to the mold, and the LED chip mounted on the pad is molded to seal and has a planar lens shape. It comprises a lens unit for condensing light and emitting to the outside.

Description

LED backlight unit {THE APPARATUS OF LED BLU}

1 is a view showing a conventional LED package shape and fastening relationship

2 is a view showing a conventional rectangular columnar flat LED package

3 is a flowchart showing a manufacturing process of a conventional LED backlight.

4 is a view showing a connection state of the LED backlight device according to the present invention

5 is a plan view of the LED backlight device according to the present invention

6 is a front view of the LED backlight device according to the present invention

7 is a partial plan view of the LED backlight device according to FIG.

8 is a partial front view of the LED backlight device according to FIG. 6

9 is a flow chart showing a manufacturing process of the LED backlight device according to the present invention

10 is a view showing another embodiment of FIG.

11 is a view showing another embodiment of an LED backlight device according to the present invention

12 is a view illustrating a configuration in which the LED backlight device of FIG. 11 is connected to a reflector;

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

10: printed circuit board (PCB) 20: LED chip

30: reflecting wall 40: reflecting plate

50: pad 60: lens unit

The present invention relates to an LED backlight device, and more particularly, to transfer an LED chip on a printed circuit board (PCB) to form a package with sufficient pressure and heat by using a mold press. By producing the LED backlight by the mold method, the package is formed integrally with the printed circuit board (PCB) rather than the case-type light emitting device, the heat generation effect is good, the light transmittance is more epoxy than the case material The present invention relates to an LED backlight device capable of obtaining a high amount of light as a low current because of being high and reducing component materials costs by miniaturizing a backlight size.

As the electronics industry develops, various display devices having small size and low energy consumption are being developed, and imaging devices, computers, and mobile communication terminals using the same are being developed. LCDs (Liquid Crystal Display), which have appeared in response to this trend, are now attracting attention as display devices such as monitors and mobile communication terminals.

Since the LCD described above does not spontaneously generate light, it is common to have a backlight composed of a light source and a light guide plate that generate light on the back of the LCD panel. In this case, the backlight generates white light so that the color of the image implemented by the LCD panel can be reproduced close to the actual color.

As described above, the backlight of the LCD has conventionally mainly used a CCFL (Cold Cathode Fluorescent Lamp) as a light source.

However, the CCFL-based backlight is subject to TCO regulation in which mercury is 2.5-3.5mg per lamp in consideration of electromagnetic wave regulations and environmental issues.There is a current leakage problem because wiring is required to connect the inverter. Its life is too short to be used for a TV at approximately 10,000 hours-50000 hours, and there is a problem of low reliability due to weak vibration and shock.

In addition, the relative light output of the various color components (e.g., red, green and blue) by the CCFL cannot be adjusted by the driving electronics or the like, and the CCFL can display a high quality image such as a video provided as a moving object on the LCD display. Not suitable for display

In order to solve the above problems, an LED backlight unit has been proposed.

Such LEDs have advantages in that they are smaller than conventional light sources, have a long lifetime, and have high energy efficiency and low operating voltages because electrical energy are directly converted into light energy.

In addition, traditionally, FL (fluorescent lamp) or CCFL (cold cathode fluorescent lamp) has been used as a light source of a backlight device for forming a surface light source used in various display devices such as advertising signs and information boards. With the advent of LEDs, LEDs having an extremely long lifespan are being positioned as light sources of various display devices instead of fluorescent lamps as conventional light sources.

As a backlighting means using LEDs, a surface light source device is obtained by providing a plurality of LEDs on the side of a light guide plate on a plane so that LED light is diffused on the light guide plate.

However, since each LED is a point light source, it is difficult to realize a high quality surface light source because it does not create an even distribution of luminance on the light guide plate.

The conventional LED backlight unit as described above needs a light guide plate to disperse the light emitted from the LED to enter the LCD panel direction. However, if the LED and the light guide plate are too close, unevenness occurs in luminance or color, and the LED may be broken by the contact of the light guide plate and the LED. However, in the related art, there is no special means for maintaining a constant distance between the light guide plate and the LED, which has the above problems.

In addition, there is a technique for forming a constant groove in the light guide plate in order to maintain the distance between the light guide plate and the LED, but the light guide plate has a difficulty in processing because the light guide plate.

There have been many efforts to solve the above problems, and in the related art, as shown in FIGS. 1 and 3, in general, after generating an LED, generating a BLU, and injecting a case for mounting the generated LED and the BLU. In addition, LED and BLU are mounted on the injected case to produce the finished product.

First, a metal pad through which electricity can pass through a lead frame is formed to emit visible light of a specific wavelength, and then an LED chip emitting light is mounted thereon (see step S300). (Refer to step S310). Then, the solid phase is converted into a liquid phase by applying heat of 170 to 180 ° C. and then injected into a mold to mold a predetermined amount of solid mold epoxy using a mold cup of a predetermined size (see step S320). The LED package is created (see step S330).

Then, insert the necessary parts such as TR to the printed circuit board to generate the backlight (BLU) (see step S340), fix the inserted parts and materials (see step S350), and separate the ARRAY product into individual elements. The individual devices are tested for electrical and optical characteristics and arranged at fixed intervals for automatic mounting during LED assembly. Then, tapping is performed to fix the tapes (see step S370).

After the above process is completed, the material is put into a specific case material for mass production (see step S380) and the object is injected (see step S390) to create a case for mounting the LED package and the BLU. Subsequently, the LED package and the BLU are mounted on the generated case to generate the LED backlight. (See step S400.)

Alternatively, as shown in FIG. 2, a square pillar type LED backlight having a flat lens is formed.

However, the solid mold for making the package of the display element and the backlight used in the conventional LED is a solid state, and the change in the physical properties of the material is narrow due to additives, compounding ratios, etc., and has a disadvantage in that its viewing angle is limited in a rectangular planar manner. have.

In addition, the transfer mold by the mold has a high thermal and mechanical limitations in the manufacturing process, making it difficult to thin the product, and the use rate of the molding material (e.g., 15%) is remarkably low, resulting in an increase in manufacturing cost and pollution. As the amount of waste resin is increased, it is followed by the cause of environmental pollution.

The present invention was devised to solve the above problems, and its purpose is to stack LED chips, which are light emitting elements, on top of a printed circuit board (PCB), transfer molds and various types of PCBs. By designing and applying a board to mount and package on a PCB board through wire bond, it is possible to provide LED backlighting device by reducing component materials cost and eliminating case materials.

In addition, another object of the present invention is to form an LED chip on the surface of the printed circuit board, the package is formed integrally with the printed circuit board (PCB) than the case of the light emitting device of the case form, the heat generation effect is good, the light transmittance is also the case It is to provide an LED backlight device that can obtain a high amount of light as a low current because the epoxy (EPOXY) is higher than the material.

In addition, another object of the present invention is that the printed circuit board (PCB) and the LED chip can be configured integrally, which can reduce the material cost due to the miniaturization of the backlight size, according to the user's use LED chip printed circuit board (PCB) The present invention provides an LED backlight device that can provide various kinds of light sources by easily changing printed circuit boards and LED elements without being bound to the place where the product is located.

According to a feature of the present invention for achieving the above object, a printed circuit board (PCB) consisting of a thin plate to which electrical components such as integrated circuits, resistors or switches are soldered to form a predetermined control circuit, and the printed circuit board A plurality of LED chips arranged on an upper surface of the PCB in a matrix form and controlled to emit light and an input current by the control circuit, disposed on an upper surface of the printed circuit board, A mold having a plurality of through holes penetrating in a front-rear direction at a corresponding position, a pad formed on an upper surface of the printed circuit board, the pad being formed of an anode and a cathode, and mounted and wire bonded to an LED chip; The external electrode terminal formed on the bottom surface of the printed circuit board and electrically connected to the pad and the LED chip mounted on the pad are sealed. Molding and, by condensing the light by the plane gateum lens shape provides an LED backlight unit that is configured to include a lens for emitting to the outside.

At this time, according to an additional feature of the present invention, it is preferable that the lens further comprises a reflective wall provided on both sides of the reflecting light.

In addition, according to an additional feature of the present invention, the cross-sectional shape of the lens unit is preferably configured to further include a rectangular cross-section in the upper convex lens shape.

In addition, according to an additional feature of the present invention, the reflective wall is formed with an inclined surface toward the lens portion to reflect the light, it is preferable to be attached to the printed circuit board by an adhesive method.

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

Figure 4 is a view showing a connection state of the LED backlight device according to the present invention, Figure 5 is a plan view of the LED backlight device according to the present invention, Figure 6 is a front view of the LED backlight device according to the present invention, Figure 7 is Figure 5 FIG. 8 is a partial front view of the LED backlight device according to FIG. 6, FIG. 9 is a flowchart illustrating a manufacturing process of the LED backlight device according to the present invention, and FIG. 11 is a view showing another embodiment, Figure 11 is a view showing another embodiment of the LED backlight device according to the present invention, Figure 12 is a view showing a configuration in which the LED backlight device according to Figure 11 is connected to the reflector.

Referring to the configuration of the present invention with reference to the accompanying drawings 4 to 8, reference numeral 10 is a printed circuit board (PCB) formed of a predetermined control circuit is composed of a thin plate soldered electrical components such as integrated circuit, resistor or switch Numeral 10 indicates a plurality of LED chips 20 arranged in a matrix form on an upper surface of the printed circuit board (PCB) 10 and whose light emission and input current values are controlled by the control circuit. ).

In addition, a plurality of through-holes (symbols) disposed on an upper surface of the printed circuit board (PCB) 10 and formed through a front and rear direction at a position corresponding to each of the LED chips 20. And a pad 50 formed on an upper surface of the printed circuit board 10 and formed of an anode and a cathode, and mounting and wire bonding of the LED chip 20. It is formed on the bottom surface of the printed circuit board 10, and constitutes an external electrode terminal (not shown) electrically connected to the pad 50.

In addition, the LED chip 20 mounted on the pad 50 is molded so as to be sealed, and has a planar lens shape, and includes a lens unit 60 that collects and emits light to the outside.

According to the skilled person in the lens unit, the cross-sectional shape of the lens unit 60 is preferably such that its upper portion has a rectangular cross section in the shape of a convex lens.

In addition, reflective walls (not illustrated) may be provided at both sides of the lens unit 60 to reflect light. At this time, the reflective wall is protruded at a predetermined height on both sides of the substrate 10 and can be positioned at a certain distance from each other, and manufactured by a separate process, molding a synthetic resin or a pure white epoxy resin having high light reflectivity and high heat resistance It is preferable to attach to the printed circuit board 10 by an adhesive method. The reflective wall attached as described above may reflect the light emitted from the LED chip 20 and more securely protect the LED chip 20 as an outer wall of the package.

The operation of the LED backlight device manufacturing method according to the present invention having the configuration as described above will be described with reference to the accompanying drawings.

As shown in FIG. 5, a plurality of circuit units are arranged in a row with each other, and a printed circuit board 10 having electrical connections is prepared for each circuit unit, and a lead guide is provided at an edge of the printed circuit board 10. The lead guide is formed to form a metal pad 50 through which electricity passes so that a light source having a specific wavelength is emitted onto the printed circuit board.

Then, the LED chip 20 is mounted on the pad 50 of the printed circuit board 10 (see step S102) to connect the LED chip 20 and the lead guide (see step S103). Bond the LED chip with wire bond epoxy as shown (see step S104).

Thereafter, an LED package is formed by a transfer molding method so as to cover the plurality of LED chips 20 arranged on the same line and the electrical connection along the plurality of arrangements of the circuit units (see step S105).

At this time, the cross-sectional shape of the molded lens unit 60 is preferably composed of a planar shape or a semi-circular shape on the top and has a rectangular cross-sectional shape.

In addition, when the blue LED chip is used as the LED chip 20 in the forming of the molded lens unit 60, it is preferable to emit white light by applying a yellow phosphor.

Meanwhile, the reflective wall may be attached to a space formed between the lens units 60 of the molded LED in the above process.

The LED package formed in the above process is cut by the printed circuit board 10 and separated for each package (see step S106), and the individual elements of the LED package are tested and fixed by tapping (see step S107).

The LED backlight device produced as described above uses a reflecting plate to protect the LED backlight. FIG. 5 shows that the LED backlight device generated by the above procedure by mounting several LED chips 20 is illustrated in FIG. 6. As shown, several LED chips 20 are protected by the reflector 40 and the light source applied by the backlight operation is irradiated through the reflector 40.

Meanwhile, in FIG. 7, in the drawing of FIG. 5, one rectangular LED chip 20 is displayed on the printed circuit board 10, and the front surface of the one rectangular LED chip 20 is illustrated in FIG. 8. As described above, the LED chip 20 is protected on the printed circuit board 10 by the reflecting plate 40, and the light source is irradiated.

5 is configured as a quadrangle of the LED chip 20, but may be mounted in a spherical shape as shown in FIG.

In addition, as another embodiment of the present invention, as shown in Figure 11 by forming a mold body having a plurality of through-holes formed to correspond to each of the series of LED chip 20 in the printed circuit board 10 The printed circuit board 10 may be configured according to the user, and as shown in FIG. 12, the reflector plate which is stacked in FIG. 11 and protected by the package which is ejected through the above series of processes and irradiates a light source upon application of power. This is composed.

As described above, the LED backlight according to the present invention may be used according to the purpose by variably configuring the printed circuit board 10 and the LED chip 20.

The present invention is not limited to the embodiments described above, it can be variously modified and changed by those skilled in the art, which is included in the spirit and scope of the present invention defined in the appended claims.

As described above, the LED backlight device according to the present invention is a transfer to form a package with a sufficient pressure and heat by using a mold press (mold press) by stacking the LED chip on the top of a printed circuit board (PCB) By producing the LED backlight by the mold method, the package is formed integrally with the printed circuit board (PCB) rather than the case-type light emitting device, the heat generation effect is good, the light transmittance is more epoxy than the case material Since it is high, a high amount of light can be obtained as a low current.

In addition, printed circuit board (PCB) and LED chip can be integrated to reduce the size of the backlight by miniaturizing the size of the backlight, and cost reduction and work because there is no need for the assembly process because the case material is unnecessary for the general LED chip. Can reduce the cost.

In addition, various LED chips can be configured on a printed circuit board (PCB) according to the user's use, so that the printed circuit board and the LED elements can be easily changed without regard to the place where the product is located. Can provide.

In addition, the LED light is formed on the upper part of the printed circuit board (PCB) as the light source, so the size and volume of the light source itself are small, so that the LED can be variously configured according to the use purpose such as general lighting, signage, and interior decoration. By long enough within the limited space so that the mixed color of the can be properly expressed the desired white (White) can maximize the utilization of the space.

In addition, it is possible to achieve an excellent productivity improvement by the ease of installing a separate reflecting wall after forming a molding lens, thereby reducing the number of applications of the LED itself to the LED using an LED light source, and approaching high brightness and high quality. The technical and economic environment of LED light source application can be improved.

Claims (4)

A printed circuit board (PCB) formed of a thin plate on which electrical components such as an integrated circuit, a resistor or a switch are soldered, and having a predetermined control circuit formed thereon; A plurality of LED chips arranged in a matrix form on an upper surface of the printed circuit board and controlled to emit light and an input current by the control circuit; A mold body disposed on an upper surface of the printed circuit board and having a plurality of through holes penetrating in a front and rear direction at a position corresponding to each of the LED chips; A pad formed on an upper surface of the printed circuit board and formed of a positive electrode and a negative electrode, wherein the LED chip is mounted and wire bonded; An external electrode terminal formed on a bottom surface of the printed circuit board and electrically connected to the pad; The LED backlight device is molded so that the LED chip mounted on the pad is sealed, and having a planar lens shape, the LED backlight device comprises a lens unit for collecting and emitting light to the outside. The method of claim 1, LED backlight device, characterized in that further comprises a reflective wall provided on both sides of the lens unit for reflecting light. The method of claim 1, The cross-sectional shape of the lens unit is an LED backlight device, characterized in that the upper portion further comprises a rectangular cross-section in the shape of a convex lens. The method according to claim 1 or 2, The reflective wall is formed with an inclined surface toward the lens portion reflects light, LED backlight device, characterized in that attached to the printed circuit board by an adhesive method.

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