CN219800896U - LED packaging structure and display device - Google Patents

Abstract

The disclosure relates to the technical field of LED packaging, and provides an LED packaging structure and a display device, wherein the LED packaging structure comprises: an LED chip; the CSP packaging layer or the NCSP packaging layer is coated on the periphery and the upper surface of the LED chip; a light diffusion layer covering the CSP packaging layer or NCSP packaging layer; the light reflecting layer is covered on the light diffusion layer, the contact surface of the light diffusion layer and the CSP packaging layer or the NCSP packaging layer is a plane, and the contact surface of the light reflecting layer and the light diffusion layer is a plane. According to the LED packaging structure, the light diffusion layer and the light reflection layer are arranged in the LED packaging structure of the CSP or NCSP, the light reflection layer is utilized to reflect light in the vertical direction of the LED chip, the reflected light is diffused through the light diffusion layer and emitted out of the periphery of the LED chip, and the light emitting of the periphery is enhanced, so that the effect of expanding the LED light emitting angle is achieved.

Description

LED packaging structure and display device

Technical Field

The disclosure relates to the technical field of LED packages, and more particularly, to an LED package structure and a display device.

Background

Currently in the display field, mini LED backlight is impacting the high-end market occupied by OLED, and the hold of Mini LED solves the problem that the life cycle of LCD products is greatly prolonged compared with the last deadly short plate of OLED. The combination of LCD plus QD film (i.e. photoluminescent quantum dot film) has formed a full overrun compared to OLED in color, but the appearance of Mini LED makes the last short plate also compensate in contrast, response speed, LCD is the last short plate compared to OLED. The Mini LED backlight accurately controls the backlight matrix switch and brightness adjustment behind the picture according to the picture change by independently controlling the backlight source, so as to realize higher contrast and faster black-and-white transition; the conventional television backlight is turned on, i.e., in a lit state, so that the backlight is operated even when the picture is in a black state, resulting in light being projected from the liquid crystal molecules, thereby greatly reducing the contrast of the display screen.

In the Mini LED backlight, the more the back LEDs are, the denser the distribution is, and the higher the control precision is, but based on the cost consideration, 1 lamp is required to be used for each partition as much as possible, so that the cost is reduced to the greatest extent. In order to meet the picture uniformity requirement, the larger the angle of the Mini LED, the better. However, the light emitted by the LED is lambertian, that is, the light intensity in the vertical direction of the chip is strongest, and when the angle is opened, the light intensity in the vertical direction of the chip is low, and the light is emitted from the side surface, so that the light emitted from the periphery is enhanced, and the effect of opening the angle is achieved.

There are two main schemes on the market: one is to spot a convex cup on a transparent packaging support to form a primary optical lens, and expand the light emitting angle of an LED from 120 degrees to 170 degrees by the lens; the other is to add a reflective layer directly above the CSP (all: chip Size Package, translating to: chip size package) or NCSP (all: near Chip Size Package, translating to: near chip size package), reflect most of the light from the front back and exit from the periphery, opening the angle.

However, both of the above solutions have certain drawbacks. Firstly, the transparent bracket point convex cup has the problem that the size of the convex cup is uncontrollable during manufacturing (the change of the light type is uncontrollable), and meanwhile, the patch is not easy to absorb during the use of a client, so that the yield is lower; in addition, the CSP and NCSP are directly added with a reflecting layer above, so that the light extraction rate is greatly reduced (the brightness is reduced by 30% -35% compared with that of the reflecting layer), the light emitted from the front is reflected vertically and then reflected repeatedly in the package body to be absorbed, and the light reflected from the front cannot be guided out from the periphery, so that the light loss is reduced.

Disclosure of Invention

The disclosure aims to provide an LED packaging structure and a display device, so as to solve the technical problem of how to enlarge the light emitting angle of an LED.

In order to achieve the above purpose, the technical scheme adopted in the present disclosure is as follows:

according to a first aspect of embodiments of the present disclosure, the present disclosure provides an LED package structure, including:

an LED chip;

the CSP packaging layer or the NCSP packaging layer is coated on the periphery and the upper surface of the LED chip;

a light diffusion layer covering the CSP packaging layer or NCSP packaging layer;

a light reflecting layer covering the light diffusing layer;

the contact surface of the light diffusion layer and the CSP packaging layer or the NCSP packaging layer is a plane, and the contact surface of the light reflection layer and the light diffusion layer is a plane.

In an alternative embodiment, the CSP packaging layer or NCSP packaging layer is a fully transparent silicone layer.

In an alternative embodiment, the light diffusing layer includes a glue layer doped with light diffusing powder having a concentration of 0.1% -10%.

In an alternative embodiment, the light diffusing powder comprises silica, titania or a powder of silica mixed with titania.

In an alternative embodiment, the CSP packaging layer or the NCSP packaging layer is a silica gel layer doped with a light diffusing powder, and the concentration of the light diffusing powder in the CSP packaging layer or the NCSP packaging layer is less than the concentration of the light diffusing powder in the light diffusing layer.

In an alternative embodiment, the concentration of light diffusing powder in the CSP encapsulation layer or NCSP encapsulation layer is less than 5%.

In an alternative embodiment, the light reflecting layer is a white glue layer containing a light reflecting material, and the concentration of the light reflecting material is 1% -50%.

In an alternative embodiment, the retroreflective material comprises titanium dioxide in solid form.

In an alternative embodiment, the thickness of the light diffusing layer is 50-500um.

According to a second aspect of embodiments of the present disclosure, there is provided a display device including the above-described LED package structure.

The beneficial effects of the present disclosure are at least: according to the LED packaging structure, the light diffusion layer and the light reflection layer are arranged in the LED packaging structure of the CSP or NCSP, the light reflection layer is utilized to reflect light in the vertical direction of the LED chip, the reflected light is diffused through the light diffusion layer and emitted out of the periphery of the LED chip, and the light emergent from the periphery is enhanced, so that the effect of expanding the LED luminous angle is achieved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings that are required for the embodiments or the description of the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and other drawings may be obtained according to these drawings without inventive effort for a person of ordinary skill in the art.

Fig. 1 is a cross-sectional view of a CPS structure of an LED package structure according to an embodiment of the disclosure;

fig. 2 is a cross-sectional view of an NCPS structure of an LED package structure according to an embodiment of the present disclosure;

fig. 3 is a schematic view of an optical path of light between a light diffusion layer and a light reflection layer according to an embodiment of the present disclosure.

Wherein, each reference sign in the figure:

1	LED chip	5	Light reflecting layer
				2	CSP packaging layer	31	Packaging adhesive
3	NCSP packaging layer	32	Substrate board
				4	Light diffusion layer

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present disclosure more clear, the present disclosure is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present disclosure.

It will be understood that when an element is referred to as being "mounted" or "disposed" on another element, it can be directly or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly or indirectly connected to the other element. The directions or positions indicated by the terms "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are directions or positions based on the drawings, and are merely for convenience of description and are not to be construed as limiting the present technical solution. The terms "first," "second," and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features. The meaning of "a plurality of" is two or more, unless specifically defined otherwise.

Referring to fig. 1 and 2, the present embodiment provides an LED package structure, including: an LED chip 1; the CSP packaging layer 2 or the NCSP packaging layer 3 is coated on the periphery and the upper surface of the LED chip 1; a light diffusion layer 4 covering the CSP packaging layer 2 or NCSP packaging layer 3; and a light reflecting layer 5 covering the light diffusion layer 4, wherein the contact surface between the light diffusion layer 4 and the CSP packaging layer 2 or NCSP packaging layer 3 is a plane, and the contact surface between the light reflecting layer 5 and the light diffusion layer 4 is a plane.

The LED package structure in fig. 1 is a CSP package technology, where the CSP package layer 2 includes a layer of packaging glue for encapsulating the LED chip 1, and the LED chip 1 is used for connecting to a circuit board (not shown in fig. 1). Specifically, as shown in fig. 1, light generated by the LED chip 1 may propagate along the optical path L1 in fig. 1, and the light reflected by the light reflecting layer 5 is refracted or diffusely reflected by the light diffusing layer 4, so that the light is emitted from the side surface of the LED chip 1.

The LED package structure in fig. 2 uses NCSP packaging technology, and the NCSP packaging layer 3 includes a layer of packaging adhesive 31 and a substrate 32, and the packaging adhesive 31 is also used to package the LED chip 1, and the LED chip 1 is connected to the substrate 32. Specifically, as shown in fig. 2, the light generated by the LED chip 1 may propagate along the optical path L2 in fig. 2, and the light reflected by the light reflecting layer 5 is refracted or diffusely reflected by the light diffusing layer 4, so that the light is emitted from the side surface of the LED chip 1.

By utilizing the LED packaging structure provided by the embodiment to carry out side light effect experiments with the existing LED packaging structure, experiments show that the maximum light emitting angle of the LED can reach 170-180 degrees, and the using quantity of Mini LEDs is greatly reduced under the same OD, so that the product cost is reduced.

Further, referring to fig. 3, after entering the light diffusion layer 4, the light generated by the led chip 1 is refracted along the light path L3, and the refracted light reaches the light reflection layer 5 and is reflected by the light reflection layer 5, and then exits through the light diffusion layer 4, and the emitted light is refracted again. Thus, the light is refracted and reflected by the light diffusion layer 4 and the light reflection layer 5 a plurality of times, and then, the light is not returned to the upper side of the LED chip 1, and is emitted from the side of the LED chip 1.

In this embodiment, the light diffusion layer 4 and the light reflection layer 5 are disposed in the LED package structure of the CSP or NCSP, the light reflection layer 5 is used to reflect the light in the vertical direction of the LED chip 1, and the reflected light is diffused by the light diffusion layer 4 and emitted from the periphery of the LED chip 1, so as to enhance the light output from the periphery, thereby realizing the effect of expanding the light-emitting angle of the LED.

The LED chip 1 may be flip-chip, front-mounted, vertical, or other chip structure types, and the LED chip 1 may be square or rectangular, or the like, and the embodiment of the disclosure does not limit the structure type and shape of the LED chip 1.

Specifically, the CSP packaging layer 2 or the NCSP packaging layer 3 has a layer of packaging glue for wrapping the LED chip 1, and the packaging glue can be configured as a fully transparent silica gel layer or a silica gel layer doped with light diffusion powder.

In one embodiment, CSP encapsulation layer 2 and NCSP encapsulation layer 3 are one layer of fully transparent silicone glue. This allows the CSP encapsulation layer 2 and the NCSP encapsulation layer 3 to have higher light transmittance, allowing more light generated by the LED chip 1 to pass through the silica gel layer into the light diffusion layer 4.

In one embodiment, the CSP packaging layer 2 and the NCSP packaging layer 3 may be silica gel layers doped with light diffusing powder, which function to assist in light diffusion.

When light diffusion powder is also added to the CSP packaging layer 2 and the NCSP packaging layer 3, the light generated by the LED chip 1 can be diffused from the ground by matching with the light diffusion layer 4, so that a larger light emitting angle can be obtained.

In one embodiment, the light diffusion layer 4 comprises a glue layer doped with light diffusion powder, and the CSP packaging layer 2 and the NCSP packaging layer 3 are silica gel layers doped with light diffusion powder, the concentration of light diffusion powder in the CSP packaging layer 2 and the NCSP packaging layer 3 being smaller than the concentration of light diffusion powder in the light diffusion layer 4.

Preferably, the concentration of the light diffusing powder may be 0.1% -10%. For example, the concentration of the light diffusion powder in the light diffusion layer 4 may be 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5%, 8.0%, 8.5%, 9.0%, 9.5% or 10%, or the like, or the concentration of the light diffusion powder may be any concentration value between any two of the foregoing, which is not limited by the embodiments of the present disclosure.

Preferably, the concentration of the light diffusing powder in the CSP encapsulation layer 2 and the NCSP encapsulation layer 3 is preferably less than 5%, for example, the light diffusing powder in the CSP encapsulation layer 2 and the NCSP encapsulation layer 3 may be 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0% or 4.5%, or the like.

Specifically, when the concentration of the light diffusion powder in the light diffusion layer 4 is also less than 5%, the concentration of the light diffusion powder in the CSP packaging layer 2 and the NCSP packaging layer 3 is less than the concentration of the light diffusion powder in the light diffusion layer 4. For example, the concentration of the light diffusion powder in the light diffusion layer 4 is 4.0%, and the concentrations of the light diffusion powder in the CSP packaging layer 2 and the NCSP packaging layer 3 are 0.5%.

In one embodiment, the light diffusing powder comprises silica, titania, or particles of silica mixed with titania.

Specifically, when light irradiates the light diffusion powder, refraction and/or reflection are generated, so that the propagation direction of the light is deflected. After light is refracted and emitted by the light diffusion powder for a plurality of times, more light can be emitted from the side surface of the LED chip 1, so that the light emitting angle of the LED chip 1 is enlarged.

In one embodiment, the thickness of the light diffusion layer 4 is 50-500um.

Wherein, the thicker the light diffusion layer 4 is, the more times the light is refracted and reflected in the light diffusion layer 4 is likely to be, the larger the angle of light emitted from the side is, but at the same time, the crown rate of the light is also reduced; the thinner the light diffusion layer 4 is, the opposite is true. For example, the thickness of the light diffusion layer 4 may be 50um, 100um, 150um, 200um, 250um, 300um, 350um, 400um, 450um or 500um, or may be any thickness between any two of the foregoing thicknesses, which is not limited by the embodiments of the present disclosure.

In one embodiment, the light reflecting layer 5 is a white glue layer containing a light reflecting material, and the concentration of the light reflecting material is 1% -50%.

Wherein the light reflecting layer 5 reflects the light emitted in the light diffusing layer 4. Therefore, the higher the concentration of the light reflecting material, the stronger the light reflecting ability to light, the more light is reflected, the stronger the light intensity of the light emitted from the surroundings, and at the same time, the light intensity emitted from the light reflecting layer 5 is also pressed lower; while the lower the concentration of the light reflecting material, the weaker the light reflecting ability, the less light is reflected, the lower the light intensity of the light emitted from the surroundings, and at the same time, the higher the light intensity emitted from the light reflecting layer 5 becomes. Therefore, a suitable concentration of the light reflecting material can be selected in practice according to the application scene.

For example, the concentration of the light reflecting material in the light reflecting layer 5 may be 1%, 4%, 7%, 10%, 13%, 16%, 19%, 22%, 25%, 28%, 31%, 35%, 38%, 41%, 44%, 47%, 50%, or the like, or may be any concentration value between any two of the foregoing, which is not limited by the embodiments of the present disclosure.

In one embodiment, the retroreflective material comprises titanium dioxide in solid form.

Specifically, titanium oxide may be used not only as a mixed material of the light diffusion layer 4 but also as a mixed material of the light reflection layer 5, which is determined by the characteristics of titanium oxide.

In one embodiment, the embodiment of the present disclosure further provides an LED packaging method, including:

step 1, fixing an LED chip 1 on a substrate by adopting an NCSP packaging process, and connecting the anode and the cathode of the chip with the anode and the cathode of the substrate by a circuit; or a CSP packaging process is adopted to arrange the flip LED chip 1 on a carrier plate;

step 2, after the LED chip 1 is fixed, covering packaging silica gel in a mould pressing mode, and heating at a set temperature to enable the packaging silica gel to be solidified to obtain an NCSP packaging layer 3 or a CSP packaging layer 2;

step 3, covering the glue layer with the light diffusion powder by molding again, and then solidifying the glue layer at a set temperature to obtain a light diffusion layer 4;

and 4, covering a layer of white reflecting layer material on the surface of the light diffusion layer 4 by molding, and solidifying the white reflecting layer material at a set temperature to obtain the light reflecting layer 5.

In the embodiment, the light diffusion layer 4 and the light reflection layer 5 are arranged above the packaging adhesive of the LED through the NCSP packaging process or the CSP packaging process, and the light emitted by the LED chip 1 is refracted and reflected, so that the NCSP or the CSP light-emitting angle is optimized, and the problem that the CSP or the NCSP has low light-emitting efficiency is solved.

The foregoing description of the preferred embodiments of the present disclosure is not intended to limit the present disclosure, but is to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the present disclosure.

Claims (4)

1. An LED package structure, comprising:

an LED chip;

the CSP packaging layer or the NCSP packaging layer is coated on the periphery and the upper surface of the LED chip;

a light diffusion layer covering the CSP packaging layer or NCSP packaging layer;

a light reflecting layer covering the light diffusing layer;

wherein the contact surface of the light diffusion layer and the CSP packaging layer or the NCSP packaging layer is a plane, and the contact surface of the light reflection layer and the light diffusion layer is a plane.

2. The LED package structure of claim 1, wherein said CSP encapsulation layer or NCSP encapsulation layer is a fully transparent silicone layer.

3. The LED package structure of claim 1, wherein the light diffusion layer has a thickness of 50-500um.

4. A display device comprising the LED package structure of any one of claims 1-3.