TWI676302B - Surface light source structure of light emitting diode - Google Patents

Abstract

The invention discloses a light emitting diode surface light source structure, which includes: a circuit board and a light emitting diode array, which are arranged on the circuit board, have a plurality of light emitting diode units, and a first isolation layer, and completely cover the light emitting diode unit. The light-emitting diode array has a first isolation height and a first isolation thickness, a light-emitting conversion layer that completely covers the first isolation layer, and has a light-emitting conversion layer height and a light-emitting conversion layer thickness, and a first Two isolation layers completely cover the light-emitting conversion layer, and have a second isolation height, a second isolation thickness, and a surface microstructure.

Description

Light emitting diode decent light source structure

The invention relates to a direct type light emitting diode surface light source structure.

The structure of the light emitting diode surface light source can be divided into two types of edge light type and direct type according to the position of the light emitting diode light source. The former is mostly suitable for small display panels, such as monitors or notebook computers, and the latter is mostly suitable for large display panels. , For example: LCD screen. The present invention mainly discloses a light-emitting diode decent light source structure suitable for a direct-type light-emitting diode. However, the current direct-type light-emitting diode decent-light source structure is mainly divided into two types of packaging: coating package and thin-film packaging. Compare the advantages and disadvantages of the package.

In the conventional light emitting diode surface light source coating and packaging, first, the light emitting diode array is first set on a circuit board, and then the light emitting conversion layer is coated and completely covers the light emitting diode array. The material of the light emitting conversion layer can be It is selected from fluorescent materials such as yttrium aluminum garnet (YAG), silicate or fluoride phosphor. This packaging method has a simple packaging process, and the packaging cost and light conversion efficiency are higher than the thin film packaging method, but with a liquid crystal screen When used, its NTSC color gamut coverage is only 80 ~ 85%.

In the conventional light emitting diode surface light source film packaging, the light emitting diode array is first set on a circuit board, and then the light emitting conversion layer film prepared in advance is covered on the light emitting diode array, and the light emitting conversion layer film can be used. The fluorescent material described above can also be a quantum dot fluorescent material. When a quantum dot fluorescent material is used, the quantum dot fluorescent material is easily affected by the temperature and humidity images and thus loses the conversion effect. An isolation layer is manufactured around the film to protect the quantum dot fluorescent material from damage. This packaging method, because the quantum dot fluorescent material can provide a narrower band of primary color light (R / G / B), so it is used with the LCD screen At this time, its NTSC color gamut coverage can reach more than 100%, but light leakage occurs at the edge of the surface light source. It is necessary to add a light shielding mechanism to the surface light source mechanism, so it can be seen that the thin film packaging method is likely to cause waste of energy. .

Therefore, in order to solve the above-mentioned problems and shortcomings of the packaging methods of light-emitting diodes, the present invention proposes a new structural design that uses sub-millimeter light-emitting diodes (Mini LEDs) to drive and emit light at ultra-low current (less than 0.1 mA). Diode arrays generate extremely low thermal characteristics, and this structure design is further proposed, but the invention should not be limited to this, but can also be applied to light-emitting diodes, sub-millimeter light-emitting diodes (Mini LEDs), or miniature light-emitting diodes. Body (Micro LED).

The invention provides a light emitting diode surface light source structure, which includes a circuit board and a light emitting diode array. The light emitting diode unit is provided on the circuit board and has a plurality of light emitting diode units and a first isolation layer, which completely cover the light emitting diode. An array, having a first isolation height, a first isolation thickness, and a light-emitting conversion layer, completely covering the first isolation layer, and having a light-emitting conversion layer height and a light-emitting conversion layer thickness, and a second isolation layer, completely covering the light-emitting conversion layer, and It has a second isolation height, a second isolation thickness and a surface microstructure.

The height of the first isolation height, the second isolation height, and the light-emitting conversion layer height is defined as a direction perpendicular to the circuit board, and the thicknesses of the first isolation thickness, the second isolation thickness, and the light-emitting conversion layer thickness are defined as being horizontal to the circuit board. direction.

Preferably, the first isolation thickness needs to be greater than or equal to the first isolation height.

Preferably, the second isolation thickness needs to be greater than or equal to the second isolation height.

Preferably, the thickness of the light-emitting conversion layer is approximately equal to (i) the height of the light-emitting conversion layer.

Preferably, the surface microstructure is a prism, lens, or cone structure, etc. Through this microstructure, the principle of light refraction can further diverge light with a larger divergence angle, correct its light path, and converge to converge, thereby obtaining more light intensity. High light source.

Preferably, the refractive index of the light-emitting conversion layer is n _q .

Preferably, the first isolation layer and the second isolation layer may be formed by stacking at least one sub-isolation layer. However, the refractive index of the sub-isolation layer is n ₁ , n ₂ , n ₃ , ..., n from the inside to the outside. _N , where N is a natural number, and should meet 1 ≦ n ₁ ≦ n ₂ ≦ n ₃ ≦… ≦ n _N ≦ n _q .

Through the above structural design, the light energy of the light emitting diode can be more fully used and the light conversion rate can be improved, and the light leakage phenomenon can be reduced to avoid waste of light energy.

In order to achieve the above-mentioned objects and effects, the technical means and structure adopted in the present invention, the features and functions of the embodiments of the present invention are described in detail in the drawings, and the size of the coating and range can be exaggerated. Yes, such content is not sufficient to qualify the invention.

Referring to FIG. 1, a schematic diagram of a light emitting diode surface light source structure according to an embodiment of the present invention. The light emitting diode surface light source structure may include a circuit board 100, a light emitting diode array 110, a first isolation layer 130a, and a light emitting conversion layer 120 in this order. And the second isolation layer 130b. The light emitting diode array 110 is disposed on the circuit board 100, between the circuit board 100 and the first isolation layer 130a, and is completely covered by the first isolation layer 130a. The light emitting conversion layer 120 is disposed on the first isolation layer 130a. Between the first isolation layer 130a and the second isolation layer 130b, wherein the second isolation layer 130b is disposed on the light-emitting conversion layer 120 and completely covers the light-emitting conversion layer 120, and the light-emitting conversion layer 120 is sandwiched between the first isolation layer 130a And the second isolation layer 130b to protect the light emitting conversion layer 120 from the influence of temperature and humidity.

The present invention may be provided as a plate body such as a flat plate body or a flexible plate body. The embodiment is described in detail with a flat structure, but it does not limit the spirit and scope of the invention. Firstly, the light emitting diode array 110 is uniformly disposed on the circuit board 100, and then a first isolation layer 130a is coated and stacked on the light emitting diode array 110 and completely covered. The first isolation layer 130a has a first isolation height. h _a and the first isolation thickness s _a , and then the light-emitting conversion layer 120 is uniformly coated and stacked on the first isolation layer 130 a and completely covered. The light-emitting conversion layer 120 has a light-emitting conversion layer height h _q and a light-emitting conversion layer thickness s. _q , wherein the light emitting conversion layer 120 may be selected from fluorescent materials such as yttrium aluminum garnet (YAG), silicate, fluoride phosphor, or quantum dot phosphor, and finally the second isolation layer 130b is uniformly coated and stack 120 to the luminescence conversion layer and completely covers, the second spacer a second spacer layer 130b having a height h _b of the second spacer thickness s _b, wherein the first release layer 130a and the second spacer layer 130b may be transparent or high haze Haze material. As mentioned above, it can be made by slit coating, wire rod coating, dip coating or spin coating.

The first isolation height h _{a is} defined as the vertical height from the surface of the circuit board 100 to the contact surface between the first isolation layer 130 a and the light-emitting conversion layer 120, and the light-emitting conversion layer height h _{q is} defined as the contact from the first isolation layer 130 a to the light-emitting conversion layer 120. surface to the contact surface 130b of the vertical height of the second spacer layer 120 and the luminescence conversion layer, and a second spacer height h _b is defined as the luminescence conversion layer 120 and the contact surface of the second spacer layer 130b to a top surface of the second spacer layer 130b are perpendicular height.

The first isolation thickness s _{a is} defined as the horizontal thickness from the edge of the edge of the light emitting diode array 110 to the contact surface between the first isolation layer 130 a and the light emitting conversion layer 120, and the light emission conversion layer thickness s _{q is} defined as being from the first isolation layer 130 a and the contact surface 120 to the light emitting luminescence conversion layer 120 and the conversion layer 130b in contact with the horizontal surface of the second spacer layer thickness, the second thickness of the barrier is defined as s _b luminescence conversion layer 120 and the contact surface of the second spacer layer 130b to the second spacer layer The horizontal thickness of the edge side of 130b.

The first isolation thickness s _a must be greater than or equal to the first isolation height h _a , and the second isolation thickness s _b must be greater than or equal to the second isolation height h _b . Its main purpose is to prevent the edge of the surface light source from condensing or being too bright. The thickness of the light-emitting conversion layer s _q needs to be approximately equal to (≒) the height of the light-emitting conversion layer h _q . In order to prevent the light-emitting conversion layer 120 from being affected by temperature and humidity, the first isolation height h _a and the second isolation height h _b must be greater than 30 μm. Isolation effect, however, the thinner the first isolation layer 130a and the second isolation layer 130b are (h _a , h _b ) or thickness (s _a , s _b ), the thinner the better the transmittance.

Referring to FIG. 2 (a), FIG. 2 (b), and FIG. 2 (c), it is a schematic diagram of a surface microstructure 240 of a light emitting diode planar light source structure according to another embodiment of the present invention. Following the features of the above embodiment, this embodiment further processes at least one surface protrusion on the top surface of the second isolation layer 230b. The surface protrusion may be a surface microstructure 240 such as a prism, a lens, or a cone, or The combination of the above structures uses the surface microstructures 240 to modify the effect of the light path and converge the light, thereby obtaining a light source with higher light intensity. The surface microstructures 240 of the present invention can be arranged regularly or Random random numbers. It should be understood that the illustrations of the embodiments of the present invention are only for those skilled in the art to understand the spirit and scope of the present invention more clearly, and should not be limited to this.

The present invention proposes another embodiment. According to the Fresnel equation, when the incident angle of light approaches zero, the light transmittance thereof conforms to 4n ₁ n ₂ / (n ₁ + n ₂ ) ² × 100%. For example: light enters glass (refractive index is about 1.5) from air (refractive index is 1), according to Fresnel equation 4 × 1 × 1.5 / (1 + 1.5) ² × 100% = 96% The transmittance is 96%. If a thin film with a refractive index of 1.2 is applied to the outer layer of glass, according to the Fresnel equation 4 × 1 × 1.2 / (1 + 1.2) ² × 4 × 1.2 × 1.5 / (1.2 + 1.5) The final transmittance obtained from ² × 100% to 98% is 98%, so it can be known that coating a thin film on the outer layer can effectively improve the transmittance effect.

To sum up, in order to improve the light conversion efficiency and the problem of improving the light transmittance, further reference is made to FIG. 3, which is a schematic diagram of a light emitting diode decent light source structure according to another embodiment of the present invention. The first isolation layer 330a and the second isolation layer 330b may be further formed by stacking at least one sub-isolation layer. As shown in the figure, the first isolation layer 330a includes at least one first sub-isolation layer and is 331a, 332a ..., 33Na in order from the inside to the outside, and the second isolation layer 330b includes at least one second sub-isolation layer and is formed from the inside. The outer numbers are 331b, 332b ..., 33Nb in order, where N is a natural number.

In order to improve the light conversion efficiency, when the refractive index of the light-emitting conversion layer 320 is _nq , the refractive indices of the first sub-isolation layers 331a, 332a ..., 33Na and the second sub-isolation layers 331b, 332b ..., 33Nb are sequentially n ₁ , N ₂ , n ₃ , ..., n _N , where N is a natural number, and the refractive index must conform to 1 ≦ n ₁ ≦ n ₂ ≦ n ₃ ≦… ≦ n _N ≦ n _q . With this structure design, more light energy can be transmitted through the light-emitting conversion layer 320 and the light-emitting efficiency of the light-emitting diode surface light source is improved.

Through the above detailed description, the object and effect of the present invention can be fully displayed. The above is only for clearly explaining the spirit and scope of the present invention, and does not limit the present invention. Therefore, those with ordinary knowledge in the art should understand that Equivalent substitutions and obvious changes made in the description and illustrated contents of the present invention are included in the protection scope of the present invention.

100, 200, 300‧‧‧ circuit boards

110, 210, 310‧‧‧‧ Light Emitting Diode Array

120, 220, 320‧‧‧‧ Luminous Conversion Layer

130a, 230a, 330a ‧‧‧ the first isolation layer

130b, 230b, 330a‧‧‧Second isolation layer

240‧‧‧ surface microstructure

331a, ..., 33Na‧‧‧The first sub-isolation layer

331b, ..., 33Nb‧‧‧Second Sub-Isolation Layer

FIG. 1 is a schematic diagram of a light emitting diode surface light source structure according to an embodiment of the present invention.

FIG. 2 (a), FIG. 2 (b), and FIG. 2 (c) are schematic diagrams of surface microstructures of a light emitting diode planar light source structure according to another embodiment of the present invention.

FIG. 3 is a schematic diagram showing a structure of a light emitting diode surface light source according to another embodiment of the present invention.

Claims (9)

A light emitting diode surface light source structure includes: a circuit board; a light emitting diode array disposed on the circuit board and having a plurality of light emitting diode units; a first isolation layer completely covering the light emitting diode A body array having a first isolation height and a first isolation thickness, wherein the first isolation thickness needs to be greater than or equal to the first isolation height; a light-emitting conversion layer that completely covers the first isolation layer and has a light emission The height of the conversion layer and the thickness of a light-emitting conversion layer; and a second isolation layer that completely covers the light-emitting conversion layer, and has a second isolation height, a second isolation thickness, and a surface microstructure. The light emitting diode surface light source structure described in item 1 of the scope of the patent application, wherein the height of the first isolation height, the second isolation height, and the height of the light-emitting conversion layer is defined as a direction perpendicular to the circuit board, and the first A thickness of an isolation thickness, the second isolation thickness, and the thickness of the light-emitting conversion layer is defined as a direction horizontal to the circuit board. According to the light emitting diode decent light source structure described in item 2 of the scope of the patent application, the second isolation thickness needs to be greater than or equal to the second isolation height. The light emitting diode surface light source structure described in item 2 of the scope of the patent application, wherein the thickness of the light emitting conversion layer is equal to the height of the light emitting conversion layer. According to the light emitting diode surface light source structure described in item 1 of the scope of the patent application, wherein the surface microstructure is a surface protrusion, which is used to modify the effect of the light path and converge the light. According to the light emitting diode surface light source structure described in item 1 of the patent application scope, wherein the refractive index of the light emitting conversion layer is n _q . The light emitting diode surface light source structure described in item 2 of the patent application scope, wherein the first isolation layer is formed by stacking at least one first sub-isolation layer. According to the light emitting diode decent light source structure described in item 2 of the patent application scope, wherein the second isolation layer is formed by stacking at least one second sub-isolation layer. According to the light emitting diode surface light source structure described in item 8 or item 9 of the scope of patent application, wherein the sub-isolation layer has an index of refraction in order from n ₁ , n ₂ , n ₃ , ..., n _N , where N is a natural number, and conforms to 1 ≦ n ₁ ≦ n ₂ ≦ n ₃ ≦ ... ≦ n _N ≦ n _q .