TWI733185B - Surface light source module for backlight device and manufacturing method thereof - Google Patents

Abstract

The present invention relates to an LED module for a backlight of a display device in which reflective parts are integrated and a manufacturing method thereof. The surface light source module of the present invention includes: a reflective member, a plate with a high reflectivity is formed with a plurality of light source holes at predetermined intervals; a sealing layer, while sealing the light source hole, while being cast on the upper surface of the reflective member, to interact with the reflective member Formed as one body; the light-shielding part is formed with a reflective pattern at a position corresponding to the light source hole and laminated on the upper surface of the sealing layer; and the light source part is mounted on the substrate at a predetermined interval, and is connected to the lower part of the reflective part The surface is combined to seal the light source in the sealing layer in the light source hole. The sealing layer is formed by sealing the inserted light source after the cast transparent resin is cured for the first time, and then cured for the second time.

Description

Surface light source module for backlight device and manufacturing method thereof

The present invention relates to a display device, and in more detail, relates to an LED module for a backlight of a display device in which a reflective member is integrally formed, and a manufacturing method thereof.

Generally, display devices include televisions (TVs) or monitors as devices that receive image signals for display. As a mechanism for displaying images, liquid crystal display devices (LCD: Liquid Crystal Display Device) and organic light emitting devices are being used. Devices (OLED: Organic Light Emitting Display), plasma display devices (PDP: Plasma Display Panel) and other devices.

Unlike other display devices, liquid crystal display devices (LCDs) cannot emit light by themselves, so if you want to display high-quality images, you must install additional external light sources. Therefore, in addition to the liquid crystal panel, the liquid crystal display device also includes a backlight device with a surface light source, so that the backlight device uniformly supplies a high-brightness light source to the liquid crystal panel, thereby embodying high-quality images. In this way, the backlight device refers to a surface lighting device such as a liquid crystal display device for realizing the image of the display device, and according to the position where the light source is arranged, it is classified into a direct lighting type or an edge lighting type. Lighting type) backlight device. As the light source of the backlight device, a light emitting diode (Light Emitting Diode, hereinafter referred to as "LED") having advantages of small size, low power consumption, and high reliability is mainly used.

Fig. 1 is a cross-sectional view showing an LED module manufactured according to the prior art.

The LED module of the direct-illumination type backlight device is manufactured by the following method: after forming the casting portion 13 in a manner of forming a cavity 14 on the substrate 11, die bonding and wire bonding are used. In this way, the LED element 12 is mounted on the substrate 11 in the cavity 14, and the cavity 14 is filled with a resin such as silicon dispersed with a phosphor to form the sealing layer 15. The sealing layer 15 has the function of protecting the LED element 12 and changing the wavelength, and the filling of the resin is suitable for dispensing molding (Dispensing Molding) or screen printing (Screen Printing).

Since this manufacturing method can cast resin on multiple LED elements 12 at the same time, it has the advantage of facilitating the manufacture of a large-area surface light source module.

However, the manufacturing method of the LED module of the prior art is realized by filling the resin in the gel state and then performing a curing process for this. During the curing of the resin, the surface appears on the contact surface of the casting part 13 A reflow 15a occurs on the surface of the sealing layer 15 under tension. The reflow 15a generated on the upper surface of the sealing layer 15 distorts the characteristics of the light emitted to the outside, and eventually causes the image quality of the display device to deteriorate.

In addition, since the LED module is printed on the circuit 11 a of the substrate 11, a height difference is inevitably formed between the substrate 11 and the casting part 13. In the manufacturing method of the LED module of the prior art, in the process of curing the resin in the gel state into a solid state, air bubbles 15b are easily generated in the height difference portion due to the inflow of air. The air bubbles 15 b generated in the sealing layer 15 weaken the durability of the LED module, cause light loss in the sealing layer 15, and distort the light characteristics emitted from the sealing layer 15. Therefore, there is a problem that the defoaming process for removing the air bubbles 15b needs to be performed.

In addition, in the LED module of the prior art, the LED element 12 is installed in the cavity 14 between the casting parts 13, and the light emitted from the LED element 12 cannot be easily diffused to the side but is concentrated to the upper side. There is a problem of large brightness deviations in the positions of the elements and the spaces between them.

[Prior Technical Literature]

[Patent Literature] Korean Patent Publication No. 10-2012-0086142 (application published on August 2, 2012, manufacturing method of LED package).

[The problem to be solved by the invention]

The object of the present invention is to provide a surface light source module and a manufacturing method thereof that can provide a reflective member on a substrate together with an LED element to exhibit high brightness, minimize brightness deviation, and exhibit uniform brightness.

In addition, the object of the present invention is to provide a surface light source module that has a uniform light-emitting surface for sealing LED elements and prevents bubbles from forming inside, thereby exhibiting excellent light characteristics, and a manufacturing method thereof.

[Means to solve the problem]

The surface light source module of the present embodiment for achieving the above-mentioned object includes: a reflective member formed with a plurality of light source holes at predetermined intervals on a plate with high reflectivity; and a sealing layer, which is molded while sealing the light source holes On the upper surface of the reflective member, it is integrated with the above-mentioned reflective member; the light-shielding member is formed with a reflective pattern at a position corresponding to the above-mentioned light source hole and laminated on the upper surface of the above-mentioned sealing layer; and the light source part is on the substrate The upper part is installed at a predetermined interval and combined with the lower surface of the reflecting member, so that the light source is sealed in the sealing layer in the light source hole, and the sealing layer is obtained by curing the cast transparent resin after the first curing. The light source is sealed and cured again for a second time to form.

Wherein, the reflecting member may include: a first reflecting surface formed on the side surface of the light source hole and having a convex curved shape; and a second reflecting surface on the upper surface of the reflecting member connected to the first reflecting surface In a flat shape.

In addition, at the lowermost end of the above-mentioned first reflecting surface, the inclination of the tangent of the curved surface can be 45° to 60° with respect to the vertical direction.

In addition, the light source and the reflection pattern can correspond one-to-one, and can be arranged such that the vertical central axis coincides.

In addition, the surface light source module of this embodiment may further include a diffusing member, and the diffusing member is combined between the sealing layer and the light shielding member.

In addition, the sealing layer may be formed on the light source hole and have the same height as the second reflecting surface.

Moreover, the method of manufacturing the surface light source module of the present embodiment for achieving the above-mentioned object includes: forming a plurality of light source holes spaced at predetermined intervals on a plate with high reflectivity to fabricate a reflective member, and step (a ), a transparent resin is cast on the upper surface of the reflective member including the light source hole to form a sealing layer; step (b), the sealing layer is cured for the first time; the light source hole is installed on the substrate at a position corresponding to the light source hole. The light source part is manufactured by using a light source, step (c), the light source part is combined with the lower surface of the reflecting member, so that the light source part is sealed in the sealing layer inside the light source hole obtained for the first casting; step (d) ), the above-mentioned sealing layer is cured for the second time.

In addition, the manufacturing method of the above-mentioned surface light source module may further include step (e). In the above-mentioned step (e), the upper surface of the sealing layer is laminated with the light shielding member formed with the reflective pattern.

In addition, the manufacturing method of the surface light source module may further include step (f). In the above step (f), a diffusion member is combined on the upper surface of the sealing layer, and the light shielding member may be laminated on the upper surface of the diffusion member.

In addition, the side surface of the light source hole may have a convex curved surface shape, and the light source hole may be connected to the upper surface of the board.

In addition, in the first curing in the step (b), curing is performed in a manner to prevent the gel-like transparent resin from having fluidity.

[Efficacy of invention]

The present invention has a reflective component on the substrate, thereby exhibiting high brightness, and the reflective component has a curved reflective surface, thereby having the effect of improving light uniformity.

In addition, the present invention does not generate reflow and bubbles during the curing of the sealing layer, so that uniform and excellent light characteristics can be exhibited.

The present invention and the technical problems achieved by implementing the present invention will be clarified by a plurality of preferred embodiments described below. The preferred embodiments of the present invention will be observed in detail with reference to the drawings attached below.

The differences in this embodiment described later should be understood as mutually exclusive matters. That is, it needs to be understood that, without departing from the technical idea and scope of the present invention, the described characteristic shapes, structures, and characteristics may be related to one embodiment to be embodied in other embodiments, and within each disclosed embodiment The position or arrangement of individual structural elements can be changed, and in the drawings, similar symbols refer to the same or similar functions in multiple respects. The length, area, thickness, etc., and their shapes can be exaggerated for ease of description. Way to express.

2 is an exploded perspective view of an LED module showing an embodiment of the present invention, FIG. 3 is a cross-sectional view in the II direction showing the main part of FIG. 2, and FIG. 4 is a side reflector of the reflection member that is the main part of FIG. 3 An enlarged view of part A, and FIG. 5 is a cross-sectional view showing the light emission characteristics of the reflective member as the main part of FIG. 2.

As shown in these figures, the LED module of this embodiment includes: a light source part 100 on which a plurality of LED elements 120 are mounted on a substrate 110; a reflective part 200 having a light source hole 210 for exposing the LED element 120, and The substrate 110 is combined; the sealing layer 300 is filled in the light source hole 210 of the reflective member 200; and the shading member 400 is combined with the upper surface of the sealing layer 300.

Specific observations are as follows. The substrate 110 constituting the light source unit 100 is used as a structure for mounting the LED elements 120 to apply power and control signals to the LED elements 120, and may be formed of a printed circuit board (PCB) or a flexible printed circuit board (FPCB). In addition, the LED element 120 is used as the light source of the LED module, and is mounted on the substrate 110 by die bonding and wire bonding, and electrical connection is achieved. The LED elements 120 are formed at a predetermined interval, and a plurality of them are installed in the horizontal, vertical and arbitrary directions. The LED element 120 may be composed of a top view element that emits light toward the upper side or a multi-faceted light emitting element including an upper light-emitting surface.

While exposing the LED element 120, the reflecting member 200 is coupled to the upper surface of the substrate 110, and diffuses and reflects the light emitted from the LED element 120. The reflective member 200 used for this is composed of a sheet or plate having high reflectivity, and a plurality of light source holes 210 are formed at positions corresponding to each LED element 120. Among them, the high reflectivity refers to the degree of excellent reflectivity that can be generally used as a reflective material in a surface light source device. The reflective member 200 has a first reflective surface 220 formed on the light source hole 210 and a second reflective surface 230 formed on the upper surface of the reflective member 200.

The first reflective surface 220 serves as the side surface of the light source hole 210, and in this embodiment, is in the shape of a convex curved surface. That is, with respect to the thickness direction of the reflective member 200, the diameter of the lower end portion of the light source hole 210 is relatively narrow, and the closer to the upper side, the greater the diameter.

The first reflective surface 220 has a convex curved surface shape, so that when the resin forming the sealing layer 300 is cured, the surface tension is relieved. Therefore, in the first reflective surface 220, no reflow occurs during the curing of the resin (refer to 15a of FIG. 1), so that the uniformity of the thickness of the sealing layer 300 and the flatness of the upper surface can be improved.

In addition, the first reflective surface 220 diffuses the light emitted from the LED element 120 toward the upper portion of the second reflective surface 230. That is, the first reflective surface 220 disperses to the upper portion of the second reflective surface 230 to concentrate the light on the upper portion of the LED element 120, thereby improving the light uniformity.

With reference to Fig. 5, the light travel path is specifically observed as follows. In part (a) of Fig. 5, when the first reflecting surface 220 is vertical, the light L1 emitted from the LED element 120 in the diagonal direction is reflected on the first reflecting surface 220. And the light is collected on the upper part of the LED element 120 again. However, in part (b) of FIG. 5, when the first reflecting surface 220 is inclined with a convex curved surface, the light L2 emitted in the diagonal direction from the LED element 120 is reflected on the first reflecting surface 220 and directed toward the first reflecting surface 220. The upper part of the two reflecting surfaces 230 is scattered. Therefore, the effect of dispersing light by the curved first reflection surface 220 is exhibited.

At this time, the first reflecting surface 220 should have a curved surface shape with a predetermined inclination of the tangent, and in this embodiment, the closer to the upper side from the lower end, the less the inclination of the tangent direction. 4, in the first reflecting surface 220, with the vertical direction as a reference, the inclination θ of the tangential direction of the lowermost end portion is 45° to 60°. When the tangential tilt θ of the first reflective surface 220 is less than 45˚, the effect of alleviating the surface tension is significantly reduced during the curing process of the resin. When the tangential tilt θ of the first reflective surface 220 is greater than 60˚, it is impossible to control the The light emitted from the LED element 120 in a diagonal direction reduces the light uniformity improvement effect to less than 50%.

The second reflective surface 230 is formed on the upper surface of the reflective member 200 to reflect the light stepped between the reflective member 200 and the light shielding member 400 upward, thereby improving the brightness of the LED module. The second reflective surface 230 extends from the first reflective surface 220 and constitutes a planar reflective surface.

The sealing layer 300 is cast on the upper surface of the reflective member 200 including the light source hole 210 to protect the LED element 120 and has a function of diffusing the light emitted from the LED element 120. The sealing layer 300 used here can be made of a highly transparent resin material. As an example, it can be made of one or more transparent materials including PS, PC, PMMA, PE, PET, PP, and MMA-styrene, as long as it has high transparency. There are no restrictions on the types of transparent materials.

The sealing layer 300 may be formed from the second reflective surface 230 including the inside of the light source hole 210 to a height of a predetermined interval. Therefore, the light emitted from the LED element 120 is sufficiently diffused in the area of the sealing layer 300 above the second reflective surface 230, so that the light uniformity can be improved. A light scattering material for light diffusion may be dispersed in the sealing layer 300, and depending on the type of the LED element 120, a phosphor for changing the wavelength of light emitted from the LED element 120 may be dispersed.

The sealing layer 300 may be formed by curing a gel-like transparent resin through a process such as dispensing molding (Dispensing Molding) and curing. In particular, the sealing layer 300 of this embodiment is combined with the light source part 100 by casting a transparent resin on the reflective member 200, and in a state where the fluidity of the resin is removed by the first curing process (pseudo curing), and then re-implementing the second It is formed by secondary curing (primary curing). Therefore, the sealing layer 300 of this embodiment is combined with the substrate 110 in a state where the fluidity of the resin is removed. Therefore, even if the electrode portion of the substrate 110 with a height difference is formed, no bubbles are generated (refer to FIG. 1 15b)

The light shielding member 400 controls the traveling direction of the light emitted to the vertical upper portion of the LED element 120 to prevent hot spots, thereby improving light uniformity. Such a light-shielding member 400 may be composed of a sheet or film having high transparency, and has a reflection pattern 410 for emitting light of the LED element 120. The light-shielding member 400 is laminated on the upper surface of the sealing layer 300 and is combined. At this time, the reflection pattern 410 corresponds to each LED element 120 at a ratio of 1:1, and is formed on a certain surface of the light shielding member 400 at a position that coincides with the vertical center axis.

As described above, in the LED module of this embodiment, a curved first reflecting surface 220 is formed in the light source hole 210 accommodating the LED element 120, so that the LED is scattered and concentrated on the upper part of the second reflecting surface 230 between the LED elements 120. The light on the upper part of the element 120 can thereby improve the light uniformity. In addition, the LED module of this embodiment relieves the surface tension at the connecting portion of the first reflective surface 220 and the second reflective surface 230, and therefore, can exhibit excellent light characteristics because it does not reflow during the formation of the sealing layer 300. Moreover, in the LED module of this embodiment, after the sealing layer 300 cast on the reflective component 200 is cured for the first time, it is combined with the substrate 110 to achieve the second curing, so that the substrate 110 and the sealing layer 300 will not be cured. Air bubbles are generated between them to improve durability and light characteristics.

Fig. 6 is a process diagram showing the process of manufacturing the LED module of the embodiment of the present invention.

Referring to FIG. 6, a transparent resin is cast at a predetermined height on the reflective member 200 where the light source hole 210 is formed to form the sealing layer 300, and the transparent resin is cured for the first time. At this time, the transparent resin can be cast by dispensing molding or screen printing process. In addition, during the first curing, the gelatinous transparent resin is cured to the extent that the fluidity is removed by the curing device.

Before the casting process, the reflective component 200 is manufactured through an additional process, and the side surface where the light source hole 210 is formed has a curved first reflective surface 220. Therefore, no reflow occurs during the curing of the transparent resin.

Moreover, the light-shielding member 400 made by an additional process is laminated on the sealing layer 300 formed by the first curing to achieve adhesion. The light-shielding member 400 should be laminated in such a way that each reflection pattern 410 coincides with the vertical central axis of the light source hole 210.

After the light-shielding member 400 is laminated, the light source unit 100 with the LED element 120 mounted on the substrate 110 is combined with the reflective member 200 with the sealing layer 300 formed thereon. At this time, the LED element 120 is located at the center of the light source hole 210 so that the vertical center axis is consistent with the reflection pattern 410. Since the light source part 100 is combined in a state where the sealing layer 300 is cured for the first time, no air bubbles are generated between the substrate 110 and the sealing layer 300 during the curing process. After the light source part 100 and the reflective member 200 are bonded together, the sealing layer 300 that has been cured for the first time is cured for the second time, thereby completely curing.

In the manufacturing process of the LED module of this embodiment, the step of laminating the light-shielding member 400 exemplifies the structure realized before bonding the light source part 100, but the light source part 100 may first be connected to the lower surface of the reflective member 200. After bonding, the light-shielding member 400 is laminated on the upper surface of the sealing layer 300.

Fig. 7 is a cross-sectional view of an LED module showing another embodiment of the present invention.

Referring to the drawings, in the LED module of this embodiment, the sealing layer 300 is only formed inside the light source hole 210. That is, the height of the sealing layer 300 is the same as that of the second reflective surface 230. Therefore, in order to ensure a space in which the light emitted from the LED element 120 is sufficiently diffused, a diffusion member 500 is also coupled to the upper surface of the sealing layer 300, that is, to the upper surface of the reflective member 200. The diffusion member 500 is made of a transparent resin material with a predetermined thickness, and as an example, a transparent plate such as PC, PS, PMMA, or the like can be used.

In addition, the light shielding member 400 having the reflective pattern 410 may be laminated on the upper surface of the diffusion member 500. The reflective pattern 410 may be directly formed on the upper surface of the diffusion member 500. In this case, the additional light-shielding member 400 may not be laminated.

As described above, although an illustrative embodiment of the present invention has been described, various modifications and other embodiments can be implemented by those of ordinary skill in the technical field to which the present invention pertains. Such modifications and other embodiments are considered and included in the scope of protection of the invention, so as not to deviate from the true purpose and scope of the invention.

11: substrate 11a: Circuit 12: LED components 13: Casting Department 14: Cavity 15: Sealing layer 15a: Reflow 15b: bubbles 100: light source 110: substrate 120: LED components 200: reflective parts 210: light source hole 220: first reflecting surface 230: second reflective surface 300: Sealing layer 400: Shading parts 410: reflection pattern 500: Diffusion component

Fig. 1 is a cross-sectional view showing an LED module manufactured according to the prior art.

Fig. 2 is an exploded perspective view showing an LED module according to an embodiment of the present invention.

Fig. 3 is a cross-sectional view in the direction of I-I showing the main part of Fig. 2.

FIG. 4 is an enlarged view showing a side reflection portion of the reflection member that is the main part of FIG. 3. FIG.

Fig. 5 is a cross-sectional view showing the light emission characteristics of the reflective member as the main part of Fig. 2.

Fig. 6 is a process diagram showing the process of manufacturing the LED module of the embodiment of the present invention.

Fig. 7 is a cross-sectional view of an LED module showing another embodiment of the present invention.

100: light source

110: substrate

120: LED components

200: reflective parts

210: light source hole

220: first reflecting surface

230: second reflective surface

300: Sealing layer

400: Shading parts

410: reflection pattern

Claims (11)

A surface light source module for a backlight device, comprising: a reflective member formed with a plurality of light source holes at predetermined intervals on a plate with high reflectivity; a sealing layer, while sealing the light source holes, is cast on the upper part of the reflective member The light-shielding member is formed with a reflective pattern at a position corresponding to the light source hole, and is laminated on the upper surface of the sealing layer; and the light source part is formed on the substrate with A plurality of light sources are installed at predetermined intervals, and combined with the lower surface of the reflecting member, so that the light source is sealed in the sealing layer in the light source hole; After the second curing, the inserted light source is sealed, and the second curing is obtained again to form. The surface light source module for a backlight device according to claim 1, wherein the reflective member includes: a first reflective surface formed on the side surface of the light source hole and in a convex curved shape; and a second reflective surface , The upper surface of the reflecting member connected to the first reflecting surface has a planar shape. The surface light source module for a backlight device according to claim 2, wherein, at the lowermost end of the first reflective surface, the tangent inclination of the curved surface forms 45° to 60° with respect to the vertical direction. The surface light source module for a backlight device according to claim 1, wherein the light source and the reflection pattern are in one-to-one correspondence and are arranged in such a way that the vertical central axis is consistent. The surface light source module for a backlight device according to claim 1, further comprising a diffusion member coupled between the sealing layer and the light shielding member. The surface light source module for a backlight device according to claim 2, wherein the sealing layer is formed on the light source hole and has the same height as the second reflective surface. A method for manufacturing a surface light source module for a backlight device includes the following steps: forming a plurality of light source holes spaced at a predetermined interval on a plate with high reflectivity to make a reflective part; step (a), including the light source hole The upper surface of the reflective part is cast with a transparent resin to form a sealing layer; step (b), the sealing layer is cured for the first time; a plurality of light sources are installed on the substrate at positions corresponding to the light source holes to make Light source part; step (c), the light source part is combined with the lower surface of the reflective member, so that the light source part is sealed in the sealing layer inside the light source hole obtained for the first casting; and step (d), curing the sealing layer a second time. The method for manufacturing a surface light source module for a backlight device according to claim 7, which further includes step (e), in which step (e), the upper portion of the sealing layer faces a light shield with a reflective pattern formed The parts are laminated. The method for manufacturing a surface light source module for a backlight device according to claim 8, further comprising step (f), in the step (f), a diffusion member is combined on the upper surface of the sealing layer; the light-shielding The member is laminated on the upper surface of the diffusion member. The method for manufacturing a surface light source module for a backlight device according to claim 7, wherein the side surface of the light source hole is in a convex curved shape, and the light source hole and the plate The upper surface is connected. The method for manufacturing a surface light source module for a backlight device according to claim 7, wherein, in the first curing of the step (b), the gel-like transparent resin is prevented from having fluidity. Curing.

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