WO2020222359A1

WO2020222359A1 - Surface light source module for backlight device

Info

Publication number: WO2020222359A1
Application number: PCT/KR2019/009186
Authority: WO
Inventors: 하지석
Original assignee: 희성전자 주식회사
Priority date: 2019-04-30
Filing date: 2019-07-24
Publication date: 2020-11-05
Also published as: TW202041935A; CN111856813A; KR20200127083A

Abstract

The present invention relates to an LED module for a backlight of a display device that can simplify the structure and manufacturing process thereof by applying a high-transparency substrate. The surface light source module of the present embodiment comprises: a circuit-printed board; a molding unit coupled to the board while providing a plurality of cavities; a light-emitting element mounted on the board inside the cavities; a sealing layer filled in the cavities while sealing the light-emitting element; and a diffusion member having a plurality of light-shielding patterns formed in positions corresponding one-to-one to the plurality of light-emitting elements and laminated on the upper surface of the sealing layer such that the vertical central axes of the light-emitting elements and the light-shielding patterns corresponding to each other coincide, wherein light emitted from the light-emitting elements is reflected and diffused by the light-shielding patterns, and is mixed and emitted in the area of the diffusion member.

Description

Surface light source module for backlight device

The present invention relates to a display device, and more particularly, to an LED module for a backlight of a display device capable of simplifying a structure and a manufacturing process by applying a highly transparent substrate.

In general, a display device is a device that receives and displays an image signal, and includes a TV or a monitor, and is a liquid crystal display device (LCD) and an organic light emitting device (OLED) as a means for displaying an image. Emitting Display), plasma display device (PDP: Plasma Display Panel), etc. are used.

Unlike other display devices, LCDs do not emit light on their own, and therefore require a separate external light source in order to realize high-quality images. Accordingly, the LCD further includes a backlight device of a surface light source in addition to the liquid crystal panel, and the backlight device uniformly supplies a high-intensity light source to the liquid crystal panel, thereby realizing a quality image. As described above, the backlight device refers to a surface lighting device for realizing an image of a display device such as an LCD, and is classified into a direct lighting type or an edge lighting type according to a position at which a light source is disposed. As a light source of a backlight device, a light emitting diode (hereinafter referred to as'LED') having advantages such as small size, low power consumption, and high reliability is mainly used.

LED devices widely used in direct-type backlight devices can primarily disperse light generated from the LED devices widely through a secondary lens so that the thickness of the backlight device can be reduced and light can be uniformly irradiated.

However, in the conventional backlight device, the overall thickness of the product is increased by inserting a specific device such as a secondary lens, and there is a limitation in making the product slimmer, lighter, or flexible, and there is a problem that the moldability is deteriorated. . In order to solve this problem, Korean Patent Publication No. 10-2015-0050655 introduces a'surface light source display device'.

As shown in FIG. 1, in the conventional surface light source display device according to the prior literature, a plurality of light-emitting elements 12 are formed on a substrate 11 while securing a predetermined distance, and the lower surface of the light-emitting element 12 A first reflective layer 13 and a second reflective layer 14 are formed on the upper and upper surfaces, respectively. In addition, the transparent resin layer 15 is filled in the space between the light emitting elements 12, and the wavelength conversion sheet 16 is coupled to the light emitting element 12 and the transparent resin layer 15.

In the surface light source display device, light emitted from the light emitting element 12 is reflected by the first reflective layer 13 and the second reflective layer 14 and is emitted to the transparent resin layer 15 on the side surface, and then is emitted upward.

The conventional surface light source display device as described above exhibits advantageous advantages in slimming and lightening. However, in the conventional surface light source display device, since the light of the light emitting element is guided to the side by the first reflective layer and the second reflective layer and is emitted, there is a disadvantage in overall luminance.

In addition, in the conventional surface light source display device, since a reflective layer is formed on an upper surface of a light emitting element, there is a problem in that light uniformity is not sufficiently mixed in a dark region by the reflective layer and a bright region therebetween.

In addition, in the conventional surface light source display device, when a top-view type light emitting device is employed in order to improve luminance, a hot spot by the light emitting device is visually recognized, thereby deteriorating light characteristics.

An object of the present invention is to provide a surface light source module that is advantageous for slimming a backlight device.

Further, an object of the present invention is to provide a surface light source module of a direct type backlight device capable of improving light uniformity by preventing hot spots while exhibiting high luminance.

The surface light source module of this embodiment for achieving the above-described problems includes: a substrate on which a circuit is printed, a molding unit coupled to the substrate while providing a plurality of cavities, a light-emitting element mounted on the substrate within the cavity, and the A sealing layer filled in the cavity while sealing the light emitting device, and a plurality of light blocking patterns formed at positions corresponding to 1:1 with the plurality of light emitting devices, and the light emitting device and the light blocking pattern corresponding to each other are vertical Including a diffusion member laminated on the upper surface of the sealing layer so that the central axis coincides with each other, light emitted from the light emitting element is reflected and diffused by the light blocking pattern, and is mixed and emitted in the diffusion member region.

Here, the sealing layer may be made of a silicone material having adhesive strength.

In addition, the light blocking pattern may be formed on an upper surface of the diffusion member, and may form a three-dimensional structure in a hemispherical, semi-elliptical, or polygonal pyramid shape.

In addition, the molding part may have a first reflective surface on a side surface of the cavity and a second reflective surface on an upper surface.

In addition, the first reflective surface may have an inclined surface or a convex curved surface shape.

In the present invention, by controlling the light uniformity by a diffusion member made of a transparent resin material and a light blocking member formed on one side thereof, a separate configuration such as a light diffusion lens is not required, thus advantageous in slimming the backlight device and simplifying the structure. have.

In addition, according to the present invention, a transparent resin may be filled in the cavity through a screen printing process, and a diffusion member may be laminated without a separate bonding process, thereby simplifying the manufacturing process and shortening the manufacturing time.

1 is a cross-sectional view showing a surface light source display device according to the prior art;

2 is an exploded perspective view showing the main configuration of a surface light source module according to an embodiment of the present subject,

3 is an I-I cross-sectional view showing the surface light source module of FIG. 2;

4 is a process chart showing the manufacturing process of the surface light source module according to the present embodiment,

5 is a cross-sectional view showing a surface light source module according to another embodiment of the present subject.

The present invention and the technical problem achieved by the implementation of the present invention will be clarified by the preferred embodiments described below. Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

It should be understood that the differences between the present embodiments, which will be described later, are not mutually exclusive. That is, without departing from the spirit and scope of the present invention, specific shapes, structures, and characteristics described may be implemented in other embodiments in relation to one embodiment, and the location of individual components within each disclosed embodiment. Alternatively, it should be understood that the arrangement may be changed, and similar reference numerals in the drawings refer to the same or similar functions over various aspects, and the length, area, thickness, and the like may be exaggerated for convenience.

2 is an exploded perspective view showing a main configuration of a surface light source module according to an embodiment of the present subject, and FIG. 3 is a cross-sectional view in the direction I-I showing the surface light source module of FIG. 2.

As shown in these drawings, the surface light source module of the present embodiment includes a substrate 100 on which a circuit is printed, a plurality of LED elements 200 mounted on the substrate 100, and an LED element 200 on the substrate 100. ) Forming a cavity 310, a molding part 300 formed to a predetermined height while forming a cavity 310, a sealing layer 400 that seals the LED element 200 while being filled in the cavity 310, a light blocking pattern ( It includes a diffusion member 500 laminated to the sealing layer 400 while having 510.

Specifically, when a predetermined circuit for driving the LED element 200 is printed, the substrate 100 may be composed of a printed circuit board (PCB) or a flexible printed circuit board (FPCB).

The LED device 200 is a light emitting source of a surface light source module, and is mounted on the substrate 100 by die bonding and wire bonding to be electrically connected. A plurality of LED elements 200 are mounted horizontally, vertically, and in arbitrary directions while forming a predetermined interval. The LED device 200 may be configured as a top view type device emitting light upward or a multi-faceted light emitting device including an upper light emitting surface.

The molding part 300 forms a cavity 310 which is a space in which the LED device 200 is mounted. For this, the molding part 300 forms a partition wall shape having a predetermined height on the substrate 100, and the height of the molding part 300 is at least higher than the LED device 200 so as to protect the LED device 200 It is preferably formed of. One or more LED devices 200 may be mounted in one cavity 310 formed by the molding part 300. The molding part 300 may be formed by bonding to the substrate 100 after a resin of an insulating material is formed in a plate shape, or by directly molding an insulating resin on the substrate 100 by a process such as insert molding.

In addition, the molding unit 300 functions as a reflective member that reflects light emitted from the LED element 200 while exposing the LED element 200 through the cavity 310. For this, the molding part 300 may be made of a material having a high reflectance. Accordingly, the molding part 300 includes a first reflective surface 320 in a vertical direction formed on the side of the cavity 310 and a second reflective surface 330 formed on the upper surface. The first reflective surface 320 forms a reflective surface in a vertical direction to reflect light emitted from the side of the LED element 200 to the optical mixing space S, and the second reflective surface 330 is a half horizontal direction. The slope is formed to reflect light reflected from the light blocking pattern 510 or distributed in the light mixing space S upwardly.

The sealing layer 400 is filled with a transparent resin in the cavity 310 to protect the LED element 200 and diffuse the light emitted from the LED element 200. For this purpose, the sealing layer 400 may be made of a resin material having high transparency, and for example, it may be made of a transparent material including any one or more of PS, PC, PMMA, PE, PET, PP, and MMA-styrene. It can be, and if it is a material having high transparency, it is not limited to the type.

The sealing layer 400 may be formed by filling the inside of the cavity 310 with a gel-like transparent resin through a screen printing process and curing it. Accordingly, the sealing layer 400 may have improved uniformity such as thickness and density. A light scattering material may be dispersed in the sealing layer 400 to diffuse light as necessary. In addition, a phosphor for converting a wavelength of light may be dispersed in the sealing layer 400 according to the type of the LED element 200.

The sealing layer 400 may also be formed on the second reflective surface 330 in order to efficiently laminate the diffusion member 500 together with the space inside the cavity 310. At this time, the thickness of the sealing layer 400 formed on the second reflective surface 330 is a thickness such that the diffusion member 500 can be adhered, and the transparent resin is used as the second reflective surface 330 according to the screen printing process. ) It is enough to print on the surface. Therefore, since the silicone resin constituting the sealing layer 400 exhibits adhesiveness by itself, the diffusion member 500 can be easily coupled even if a separate adhesive means is not applied.

The diffusion member 500 is bonded to the upper surface of the sealing layer 400 to protect the sealing layer 400 and provide a light mixing space S in which the light emitted from the LED device 200 is mixed. The diffusion member 500 for this may be made of a resin having high transparency, and for example, a transparent sheet or plate such as PC, PS, or PMMA may be used.

Further, the diffusion member 500 has a thickness at which a minimum optical distance OD is secured in order to sufficiently perform optical mixing. Accordingly, the surface light source device of the present embodiment may provide a surface light source device showing the best light uniformity by applying the diffusion member 500 having a predetermined thickness according to the emission characteristics of the LED element 200. In this embodiment, the diffusion member 500 may have a thickness of 0.05 to 4.5 mm.

In addition, the diffusion member 500 includes a light blocking pattern 510. The shading pattern 510 reflects and diffuses the light emitted from the upper surface of the LED device 200 into the space between the LED devices, thereby improving overall light uniformity of the light emitted from the surface light source module. For this, the light blocking pattern 510 may be formed by coating ink or resin having a predetermined reflectance on the upper surface of the diffusion member 500.

In addition, the light blocking pattern 510 has a diameter larger than the light exit surface of the LED device 200 at least, and may form a three-dimensional structure of a hemispherical shape, a semi-elliptic shape, or a polygonal pyramid shape. In addition, a plurality of shading patterns 510 are formed at positions corresponding to the LED element 200 in a 1:1 manner. The diffusion member 500 having the light blocking pattern 510 is directly adhered to the upper surface of the sealing layer 400 by laminating. This is because, as the sealing layer 400 is made of a resin material such as silicone, the diffusion member 500 can be easily adhered without a separate adhesive member.

The surface light source module of this embodiment is advantageous in slimming the backlight device because a separate configuration such as a light diffusion lens is not required by controlling the light uniformity by a diffusion member made of a transparent material and a light blocking member formed on one surface thereof. It has the effect of simplifying and can be manufactured by a process of directly laminating the diffusion member without a separate adhesive member, thereby simplifying the manufacturing process.

4 is a flowchart showing a manufacturing process of the surface light source module according to the present embodiment.

Referring to FIG. 4, in the surface light source module of this embodiment, a substrate 100 on which an LED element 200 is mounted and a molding part 300 formed along the periphery of the LED element 200 is prepared. The molding part 300 may be formed by manufacturing a plate in which the cavity 310 is formed and bonding to the substrate 100, or by directly molding an insulating resin on the substrate 100. After the substrate 100 is prepared, a transparent resin is filled in the cavity 310 by using screen printing as shown. The filling of the transparent resin can be sufficiently performed by screen printing about 1 to 2 times, so that the process time can be shortened, and at the same time, the filled transparent resin can have excellent uniformity. The filled transparent resin is cured under conditions to form a sealing layer.

Then, a diffusion member 500 having a light blocking pattern 510 formed on one surface thereof is manufactured and prepared in a separate process, and the diffusion member 500 is laminated on the upper surface of the sealing layer 400 using a rolling device. In this case, the plurality of shading patterns 510 and the LED element 200 must be corresponded to each other in a 1:1 manner, and laminated so that the corresponding shading patterns 510 and the vertical central axis of the LED element 200 coincide. Since the diffusion member 500 is adhered using the adhesive force of the sealing layer 400, a separate molding process for bonding may be eliminated.

In addition, the surface light source module is completed by laminating the diffusion member 500 and then removing the protective paper 500 ′ protecting the light blocking pattern 510.

In the surface light source module of the present embodiment, the first reflective surface 320 provided in the molding part 300 has an inclined surface structure. That is, the first reflective surface 320 is inclined upward so that the width of the cavity 310 increases as it goes upward. The first reflective surface 320 having such an inclined structure may further improve light uniformity by dispersing light emitted from the LED device 200 into a space between the LED devices.

Further, although not shown, the first reflective surface 320 may have a convex curved shape. Since the curved first reflective surface 320 does not form a bent corner at the connection portion between the first reflective surface 320 and the second reflective surface 330, the first reflective surface 320 and the second reflective surface 330 ) To alleviate the surface tension that may occur on the surface of the joint. Therefore, the first reflective surface 320 having a convex curved shape minimizes the occurrence of reflow due to surface tension when the transparent resin for forming the sealing layer 400 is cured, thereby preventing deterioration of optical properties due to reflow. I can.

Although the exemplary embodiments of the present invention have been shown and described as described above, various modifications and other embodiments may be made by those skilled in the art. These modifications and other embodiments are all considered and included in the appended claims and will not depart from the true spirit and scope of the present invention.

Claims

A printed circuit board;

A molding unit coupled to the substrate while providing a plurality of cavities;

A light-emitting element mounted on the substrate inside the cavity;

A sealing layer that is filled in the cavity while sealing the light emitting device; And

A diffusion member having a plurality of light-shielding patterns formed at positions corresponding to the plurality of light-emitting elements 1:1, and laminated on an upper surface of the sealing layer so that the vertical central axes of the light-emitting elements and the light-shielding patterns correspond to each other; Including,

A surface light source module for a backlight device, wherein the light emitted from the light emitting device is reflected and diffused by the light blocking pattern, and is mixed and emitted within the diffusion member region.
The method of claim 1, wherein the sealing layer,

A surface light source module for a backlight device, which is made of a silicone material with adhesive strength.
The method of claim 1, wherein the light blocking pattern,

A surface light source module for a backlight device, which is formed on the upper surface of the diffusion member and forms a three-dimensional structure of a hemispherical, semi-elliptical or polygonal pyramid shape.
The method of claim 1, wherein the molding part,

A surface light source module for a backlight device having a first reflective surface on a side surface of the cavity and a second reflective surface on an upper surface.
The method of claim 4, wherein the first reflective surface,

A surface light source module for a backlight device that forms an inclined surface or a convex curved surface shape.