KR20100091384A - Embedded direct led bare chip array backlight unit and manufacturing for the same - Google Patents

Abstract

The present invention relates to a light emitting device and a method for manufacturing the same, and a backlight device using the same. The present invention relates to an LED chip 17 and a printed circuit board 15, which are integrated into a series, and are stably arrayed in series. The present invention relates to an LED bare chip backlight unit that is directly buried and embedded.

According to the present invention, a plurality of direct type LED bare chips 17 are directly attached to the upper surface of the printed circuit board, rather than the existing chip type LED chip package 16, and the lower type LEDs are attached to the lower portion of the printed circuit board. A plurality of heat dissipation conductive holes 116 are arranged to allow heat generated by the backlight unit to be discharged to the outside. The structure has a printed circuit board 15 having a role of fixing the transparent or LED chip 17 on the upper part and at the same time containing the material to control the light of the LED in the form of an opening 119, the lower side of the As a printed circuit board, a circuit including a bonding pad is formed on one side thereof, and opposite circuits on both sides form a ground 201 that functions to radiate heat, and then a heat conduction hole for connecting the upper circuit and the lower circuit of both sides ( 116). Thereafter, the two printed circuit boards are laminated with an adhesive such as an adhesive bonding sheet 118 or a prepreg.

Description

Buried direct type LED array backlight unit and manufacturing method thereof {EMBEDDED DIRECT LED BARE CHIP ARRAY BACKLIGHT UNIT AND MANUFACTURING FOR THE SAME}

The present invention relates to a direct type backlight unit using an LED bare chip and a manufacturing method thereof, and more particularly, a structure in which the LED chip 17 is bonded 113 to the direct board 114 instead of the LED package 16. The present invention relates to a buried direct type backlight unit and a method of manufacturing the same, which are thinner and have a simplified production process.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit unit for a liquid crystal display device. More specifically, the LED chip 17 is directly array-bonded to the printed circuit board 15 without the LED package 16. The present invention relates to a direct type backlight unit capable of stable and simple manufacturing and finally slimming of display thickness.

Recently, as the information society has evolved rapidly, the necessity of a flat panel display device having excellent characteristics such as slimness, light weight, and low power consumption has emerged. Among these, liquid crystal display devices are excellent in resolution, color display, image quality, and the like. It is actively applied to displays such as monitors and LCD TVs. Domestically and internationally, the thickness of the BLU products has a significant impact on the display, which ultimately raises the issue of which technology of which company is the most slim and competitive in price.

In general, a liquid crystal display device is formed by arranging two substrates on which electric field generating electrodes are formed so that the surfaces on which two electrodes are formed face each other, injecting a liquid crystal material between the two substrates, and then applying a voltage to the two electrodes. By moving the liquid crystal molecules by an electric field, the device expresses an image by the transmittance of light that varies accordingly.

However, the liquid crystal display does not emit light by itself and merely controls a light transmittance, and thus requires a separate light source.

Therefore, an image is displayed by arranging a backlight on the back of the liquid crystal panel and injecting light from the backlight into the liquid crystal panel to adjust the amount of light according to the arrangement of the liquid crystals.

Such a backlight is divided into a direct method of directly dimming the front surface of the substrate by placing a light source on the bottom of the liquid crystal panel and an edge method of reflecting and diffusing light by a light guide plate and a reflecting plate by placing the light source on one or both sides of the liquid crystal panel.

The direct method does not need a light guide plate because the light emitted from the lamp is directly emitted to the front of the liquid crystal panel, whereas the edge method requires a light guide plate that emits the light emitted from the side lamp to the front of the backlight. In general, the backlight used in notebook computers and LCD monitors adopts an edge method with low luminance unevenness, thin film shape, and low power consumption. Direct type backlights are also widely used in large screen liquid crystal displays because they have high light utilization, easy handling, and no limitation on the size of the display surface.

Of course, the number of light sources will also increase in order to realize high brightness in the direct-type backlight, and all components at the time of replacement due to failure or failure of each component generated during assembling or use of the liquid crystal display device with many light sources installed. Dismantled all of them, there was a disadvantage to take the inconvenience of reassembling after replacement work.

In the case of a direct backlight method, a conventional production process includes a process of manufacturing a printed circuit board, a process of bonding the LED chip 17 to a substrate, and a process of cutting the bonded substrate into respective chip packages 16. And surface-mounting (SMT) the chip package 16 on a separate substrate, bonding the injection-molded product 117 with openings thereon, and dispersing and fixing epoxy on the substrate. The backlight unit is manufactured by the process of making it.

The technical problem to be achieved by the present invention is to configure the LED backlight unit integrally by bonding the LED in the bare chip 17 state to the direct board 113, to simplify the structure and to make the process stable and simple production, the thickness It is an object of the present invention to provide an ultra-thin direct type embedded backlight unit.

The direct backlight unit according to the present invention is largely divided into a structure of an upper printed circuit board (PCB) 114, an intermediate adhesive layer 118, and a lower double side printed circuit board (115).

The upper printed circuit board includes an insulating film having a plate hole type or the like opening 119 therethrough, a circuit board 117 including a first conductive film and a second conductive film formed on both surfaces of the insulating film; It includes a structure for accommodating the LED bare chip in the opening 119 of the circuit board having an opening.

The second printed circuit board 115 below the printed circuit board 114 is made of epoxy, an insulating material such as FR4 or BT RESIN, and a conductor is laminated on both sides thereof. The upper circuit of) has a structure in which the LED chip is loaded and can be wire bonding 113, and a bonding pad is located and connected to a power supply and a drive chip. The lower circuit 201 is formed with a through-conducting hole 116 conducting from the position of the upper LED chip 17 and a position near the lower circuit 201, and the hole is formed with patterns of the ground 201 for heat dissipation of the lower circuit. It is connected to prevent the heat of LED effectively.

The printed circuit board 114 including the upper opening 119 described above and the lower double-sided printed circuit board 115 are bonded to the middle portion by a laminating adhesive bond 118 such as, for example, a prepreg. To form an integral part.

The material of the printed circuit board 114 having the opening 119 may include an insulating material such as epoxy, polyimide, and BT RESIN.

The lower printed circuit board 115 may use various thicknesses, such as 1/3 ounce, 1/2 ounce, and 1 ounce, depending on the amount of current of the LED in the upper circuit of the double-sided circuit.

The lower heat dissipation ground 201 of the lower printed circuit board 115 is intended for heat dissipation, and may be used in various kinds of one-ounce, two-ounce and aluminum panels.

The opening 119 of the upper plate printed circuit board 114 having the opening 119 is not affected by its shape, and the bottom portion of the upper portion of the printed circuit board 114 is narrow in size suitable for the LED chip 17. The upper portion of the opening 119 is preferably formed larger than the lower surface of the opening to form a plate shape so that the light of the LED can effectively escape.

The circuit board of the direct backlight unit manufactures the openings 119 of the printed circuit board 114 of the upper plate, forms the circuit of the lower circuit board 115, and then uses the adhesive 118 to form two circuit boards. Laminate and bond to complete the substrate.

In another method of manufacturing the circuit board of the direct backlight unit, a single-sided board is prepared without forming and attaching a printed circuit board of the upper and lower boards to two substrates, and a half hole (half hole) on the upper surface of the substrate. It can also be prepared by forming a.

The structure of the direct type backlight unit is an LED 17, but the present technology process may be applied to other semiconductor packages other than the LED.

 The direct type backlight unit includes application to all displays requiring a light emitter such as mobile, PMP, navigation, monitor, TV, and the like.

The direct type backlight unit directly embeds the LED chip 17 to wire bond 113 and arrays a plurality of LED chips 17 to be applied from a small display to a large display. There is no need for a separate hole cup-type injection molding 117 for dispensing and molding the chip 17.

As described above, according to the present invention, in order to install a large number of light sources, the existing direct type backlight unit packages the LEDs 16 and places them on substrates such as the printed circuit board 112 with surface mounting equipment (SMT). After this, it was cut again and used in one or several lines. In another recent patent application, a chip array direct backlight type unit is embedded with a chip, but as an existing injection molding 117 is required separately, even if the chip is embedded, the array is not arranged without a method to reduce the thickness. Its features did not improve thickness and productivity.

The present invention improves and solves these problems, eliminating the surface mounting (SMT) process, directly arranging the chip 17 and bonding to the substrate 115, embedded in the printed circuit board 114 and a separate injection molding (117) It was possible to reduce the process cost significantly without manufacturing.

The number of production steps has been drastically reduced, thus eliminating the process of making the existing package 16 and eliminating surface mounting (SMT), thereby significantly increasing production efficiency.

At the same time, it is possible to establish an environmentally friendly process that does not use environmentally harmful substances by removing lead, which is a harmful component generated during the surface mount (SMT) process.

Although the present invention has been described with reference to the above embodiments, it is merely illustrative, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. . Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

LED chip array direct type backlight unit according to the present invention for achieving the above object,

A plurality of LED chips 17 separated from each other at predetermined intervals are embedded in the upper printed circuit board 114 having the openings 119 formed therein, and the pads of both sides of the printed circuit board having the circuits of the lower board 115 formed thereon. It is connected to and driven by the bonding, and the LED chip 17 and the wire bonding 113 is fixed, without the need for a separate cup-shaped injection molding 117 is installed to mold the phosphor, the opening 119 is injection molding 117 It is characterized in that the discharge of the fluorescent liquid, such as phosphor and epoxy to the opening 119 to the opening (119).

A plurality of conductive through holes 116 are formed in the lower pattern 201 of the lower printed circuit board 115 to be connected to the heat dissipation ground 201 of the lowermost layer, and heat generated by driving the direct type LED backlight unit. A plurality of integrated, embedded, and direct type LED backlight units having a heat dissipation ground (201) attached to them to be discharged to the outside.

The direct type LED backlight unit does not have a limit in length in one direction due to its size limitation in an array process, but the arrangement of the LEDs in one direction, two lines, and three lines in one direction of another right angle. It is to provide a direct backlight unit including a method in which the arrangement varies depending on the possible working size.

In addition, the opening 119 of the direct type LED backlight unit may be formed in various shapes in addition to a circle, a rectangle, and a pentagon, and may be formed in a straight shape and a plate shape on the side.

The lower printed circuit board 115 of the direct type LED backlight unit is preferably formed by stacking conductive copper on an insulating material such as FR4, Polyimide, BT Resin,

The thickness of the conductive material of the printed LED board of the direct type LED backlight unit can be changed according to the amount of current, but in the case of the lowermost conductor 201, it is preferable to set it to 1 oz or more to smooth heat dissipation function. This can also be changed to various thicknesses by design specifications.

In the direct type LED backlight unit according to the present invention, a driving element may be integrally located in the unit for driving the backlight unit, or may be attached to the outside of the unit to drive the backlight unit.

The direct type backlight unit includes a connector for power and driving, and includes a separate passive device.

The direct type backlight unit may apply the white ink 200 to the surface to more easily disperse the light, and may include using a white substrate to produce an effect such as light dispersion separately from the white ink. have.

According to another embodiment of the present invention, a direct type backlight unit includes: a circuit board (115) for applying an electrical signal to each of the direct type LED arrays;

A printed circuit board 114 including an upper opening for protecting the chip and containing a liquid phase;

Located in the lower portion of the direct type LED, the through hole for transmitting heat to the conductor to the conductor 116 for heat radiation;

Located in the lower portion of the direct type LED, and includes a conductor in the form of a ground to emit heat of the LED to the outside (201).

According to the present invention, it is possible to reduce the production cost by forming a fixing means, for example, a mold, such as an epoxy liquid, without a separate injection molding 117 or by reducing the height and thickness to the opening, thereby reducing the production cost and forming a slimmer body. Can be.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

1 is a view showing the configuration of a buried LED backlight printed circuit board of a direct backlight unit according to the present invention, Figure 2 is a conventional patent of a direct package backlight unit of the LED package surface mounting (SMT) type (Publication No. 10- 2008-0018309, -LG Innotek), FIG. 3 is an array of direct backlight units without surface mounting (SMT), but as in surface mounting, separate injection moldings have to be raised separately so that the thickness becomes thick again and the process remains intact. Figure 4 is a structure of the example unit having, Figure 4 is a side view enlarged view of the state of the side to confirm the array state of the direct type backlight unit according to the present invention is formed without a separate injection, Figure 5 is a surface mounting (SMT) type Side assembly view, which is assembled with an assembly panel with a direct backlight unit of FIG. 6 and an LCD panel according to the present invention. FIG side assembly, which is assembled in the lower die backlight unit 7 is a view design an example of a circuit system diagram in accordance with the present invention.

First, as shown in the drawing, the direct type backlight unit according to the present invention has a plurality of openings having a plurality of hole cup functions in an upper portion of a printed circuit board, an adhesive layer is disposed at a lower portion thereof, and a circuit in which the LED chip is bonded at a lower portion thereof. A conductive hole connecting the pattern and the lowermost ground to the conductor, the ground circuit as the lowermost heat sink, and the surface except the plurality of LED packages so that the light emitted from the direct LED backlight unit is reflected to the front, or printed and Ink to be bonded and a white insulating plate are formed.

In order to eliminate the process of making a package using the injection from the existing LED package, such as surface mounting (SMT), in the present invention, the injection molding function is integrally manufactured with the printed circuit board, and the bare LED chip is directly arrayed there. Bonding has significantly reduced its thickness and structure, and made it possible to produce batches from small display backlight units for mobile devices to large display backlight units for LCD TVs.

1 is a structural diagram of stacking two array printed circuit board according to the present invention.

Figure 2 is a view showing the configuration of the assembled LED module of the conventional direct type backlight unit of the package type to form an LED chip package and again accompanied by surface mounting (SMT),

3 is an example of a frame of a direct type backlight unit that does not have an SM, but is accompanied by a chip array and the injection molding is to be placed on it, so that the thickness improvement is not obvious as shown in FIG.

Figure 4 is a view showing an embodiment of assembling the present invention patent direct LED chip backlight unit of the chip direct bonding array type is not accompanied by SM and in accordance with the present invention,

5 is an enlarged view of a side of an assembled state capable of confirming the assembling state of the direct type backlight unit with the SMMT;

6 is an enlarged partial side view showing an assembled state of the direct type backlight unit according to the present invention;

7 is a diagram illustrating a design of a direct type backlight unit according to the present invention;

* Explanation of Signs of Major Parts of Drawings *

LCD panel: 10 Optical sheet: 11

Guide panel: 12 Case top: 13

Cover Bottom: 14 PCB: 15

LED package: 16 LED chip: 17

Lens: 100 Top Substraight: 111

Top PCB: 114 Bottom substrate: 112

Bottom PCB: 115 Wire Bonding: 113

Heat dissipation hole / Conducting hole: 116

Adhesive Layer: 118 Opening: 119

White print: 200 ground: 201

Claims (16)

A printed circuit board of the upper plate in which an upper portion is formed in an array of a plate-shaped opening larger than the lower portion, or a cup-shaped opening such as hole sizes in the upper and lower portions thereof, and an insulating material such as FR4, BT Resin, or Polyimide, and a lower portion thereof. And a printed circuit board having conductors stacked on both surfaces thereof, and wherein the upper and lower printed circuit boards are integrally bonded to each other. The method of claim 1, The direct type LED backlight unit of claim 1, wherein the LED chip in the bare state is mounted and wire-bonded. After the internal chip bonding of the opening, the direct-type LED backlight unit, characterized in that it further comprises a phosphor and an epoxy liquid as a molding member. Direct LED backlight unit further comprises a lens for evenly dispersing light in the upper portion of the opening. A direct type LED backlight unit comprising the application and printing of white ink or the stacking of white insulators for effective dispersion of light in portions other than the openings. The lower printed circuit board of the opening has a double-sided conductor structure. The middle layer is formed of an insulator such as FR4, Polyimide, BT Resin, and the upper part of the insulator is formed to drive an LED array. Direct type LED backlight unit, characterized in that comprising a ground to be made. And a direct conducting hole for connecting the upper circuit and the lower circuit of the lower printed circuit board with a heat dissipation structure. The circuit is located on the bottom surface of the lower printed circuit board is formed as a ground for heat dissipation, in addition to the direct type LED backlight unit, characterized in that the addition of a heat sink such as aluminum. And a bare LED chip array of the direct backlight unit is directly wire-bonded to the circuit board, and the array thereof is arranged in a matrix or zigzag form and connected in series. A direct backlight unit, characterized in that integrated by bonding the chip inside the printed circuit board and covered with a molding from above. A direct backlight unit, characterized in that the entire array is formed in one piece by directly bonding the LED chips to the circuit board without using a separate injection molding product. The LED chip is a direct type backlight unit including one or more of red, green, blue, white. The array includes a direct type backlight unit including arranging one or more LEDs on a circuit board. And at least one connector for supplying power to a driving series circuit below the circuit board. And a driving chip may be stored in the lower driving series circuit on the circuit board. The direct backlight unit, characterized in that when bonding the LED chip on the circuit board is bonded by any one or a combination of a bonding sheet, epoxy, conductive adhesive, adhesive.

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