A uniformly luminous LED device

Abstract

The present invention discloses a uniformly luminous LED device, relating to the field of semiconductor light-emitting. The uniformly luminous LED device includes a light-emitting unit electrically connected to a first conductive component and a second conductive component; the first conductive component is provided with a first supporting area and a first reflecting area, the first reflecting area having a first height difference relative to the first supporting area; the second conductive component is provided with a second supporting area and a second reflecting area, the second reflecting area having a second height difference relative to the second supporting area; an optical lens is located above the light-emitting unit, the first conductive component, and the second conductive component, and is connected to the first conductive component and the second conductive component; the bottom of the light-emitting unit is connected to the first supporting area and the second supporting area, respectively. This LED device does not require complex secondary optics, and provides uniform light emission at low cost and with high reliability.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor light emitting technology, and in particular to a uniformly luminous LED device. Background Art

[0002] LED light sources are widely used due to their low power consumption, high brightness, and long lifespan. However, their luminous properties inherently follow Lambert's cosine law (I(θ)=Incosθ), meaning that light intensity is strongest in the normal direction and decreases significantly as the angle θ increases. This unevenness requires secondary optical homogenization (e.g., PC, PMMA, glass, or silicone lenses) in applications requiring uniform lighting (such as backlighting and medical equipment). However, existing materials present the following issues:

[0003] Poor temperature resistance: PC and PMMA have a long-term temperature resistance of only 70-100°C and cannot be used in high temperature environments;

[0004] High cost: Glass and silicone are difficult and expensive to process.

[0005] Therefore, there is an urgent need to develop a uniformly emitting LED device that does not require complex secondary optics, is low-cost, and has high reliability. Summary of the Invention

[0006] The technical problem to be solved by the embodiments of the present invention is that the LED light source is strongest in the normal direction and significantly attenuates as the angle θ increases.

[0007] In order to solve the above problems, an embodiment of the present invention discloses a uniformly emitting LED device, which achieves uniform emitting effect without complex secondary optics, low cost and high reliability.

[0008] The present invention provides a uniformly luminous LED device, which includes a light-emitting unit, which is electrically connected to a first conductive component and a second conductive component respectively; the first conductive component is provided with a first supporting area and a first reflecting area, and the first reflecting area has a first height difference relative to the first supporting area; the second conductive component is provided with a second supporting area and a second reflecting area, and the second reflecting area has a second height difference relative to the second supporting area; an optical lens is above the light-emitting unit, the first conductive component and the second conductive component, and is connected to the first conductive component and the second conductive component; the bottom of the light-emitting unit is connected to the first supporting area and the second supporting area respectively.

[0009] A further technical solution is that the light-emitting unit is a front-mounted structure; the light-emitting unit includes a first electrical connection end and a second electrical connection end, the first electrical connection end is connected to the first reflective area through a first bonding wire, and the second electrical connection end is connected to the second reflective area through a second bonding wire.

[0010] A further technical solution is that the light emitting unit is connected to the first bearing area via a first connecting medium, and the light emitting unit is connected to the second bearing area via a first connecting medium.

[0011] A further technical solution is that the light-emitting unit is a flip-chip structure; the light-emitting unit includes a third electrical connection end and a fourth electrical connection end, the third electrical connection end is connected to the first supporting area, and the fourth electrical connection end is connected to the second supporting area.

[0012] A further technical solution is that the first electrical connection end is connected to the first bearing area via a second connection medium, and the second electrical connection end is connected to the second bearing area via a second connection medium.

[0013] A further technical solution is that the first bearing area and the second bearing area are located in the same reference plane.

[0014] A further technical solution is that the bottom surfaces of the first conductive component and the second conductive component are both flat surfaces.

[0015] A further technical solution is that the surfaces of the first reflective area and the second reflective area are subjected to smooth metallization treatment, and the smooth metallization treatment includes at least one of electroplating silver, electroplating gold, chemical immersion gold, chemical immersion tin or tin spraying process.

[0016] A further technical solution is that the surface of the first reflection area is any one of a plane, a concave arc surface or a compound curved surface, and the surface of the second reflection area is any one of a plane, a concave arc surface or a compound curved surface.

[0017] A further technical solution is that the optical lens includes at least two free-form surfaces, a concave area is formed at the connection between the two free-form surfaces, and the concave area is directly above the light-emitting unit.

[0018] Compared with the prior art, the embodiments of the present invention can achieve the following technical effects:

[0019] The surface height of the first supporting area is greater than the surface height of the first reflecting area, and the surface height of the second supporting area is greater than the surface height of the second reflecting area. The light emitted by the light-emitting unit is reflected by the first reflecting area and the second reflecting area, so that the luminous intensity at the center of the LED device and the luminous intensity on the four sides are more uniform, without the need for secondary optical homogenization processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 A schematic structural diagram of a uniformly luminous LED device provided by an embodiment of the present invention;

[0022] Figure 2 A schematic structural diagram of another uniformly emitting LED device provided by an embodiment of the present invention;

[0023] Figure 3 A schematic structural diagram of a uniformly luminous LED device (the light-emitting unit is a flip-chip structure) provided by an embodiment of the present invention;

[0024] Figure 4 This is a structural schematic diagram of a uniformly luminous LED device (the light-emitting unit is a front-mounted structure) provided by an embodiment of the present invention.

[0025] Reference numerals

[0026] 1. Light-emitting unit; 2. First conductive component; 3. Second conductive component; 4. Optical lens; 5. Connector;

[0027] 21. First bearing area; 22. First reflection area; 31. Second bearing area; 32. Second reflection area; 6. Concave area;

[0028] 11. First electrical connection end; 12. Second electrical connection end. DETAILED DESCRIPTION

[0029] The following will be combined with the accompanying drawings of the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments. Similar component numbers in the drawings represent similar components. Obviously, the embodiments described below are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0031] It should also be understood that the terms used in this description of the embodiments of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present invention. As used in the description of the embodiments of the present invention and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0032] See also Figure 1-Figure 4 , an embodiment of the present invention provides a uniformly luminous LED device. The uniformly luminous LED device includes a light-emitting unit 1, which is electrically connected to a first conductive component 2 and a second conductive component 3 respectively; the first conductive component 2 is provided with a first supporting area 21 and a first reflecting area 22, and the first reflecting area 22 has a first height difference relative to the first supporting area 21; the second conductive component 3 is provided with a second supporting area 31 and a second reflecting area 32, and the second reflecting area 32 has a second height difference relative to the second supporting area 31; an optical lens 4 is above the light-emitting unit 1, the first conductive component 2 and the second conductive component 3, and is connected to the first conductive component 2 and the second conductive component 3. The specific introduction of each component is as follows:

[0033] In this embodiment, the optical lens 4 forms a covering structure, the inner surface of which is tightly fitted with the side surfaces of the first conductive component 2 and the second conductive component 3; the bottom surfaces of the first conductive component 2 and the second conductive component 3 are completely exposed outside the covering structure, and the exposed bottom surfaces of the first conductive component 2 and the second conductive component 3 are soldered to the circuit board. The first conductive component 2 and the second conductive component 3 are both made of copper and are electrically connected to the first electrical connection terminal 11 and the second electrical connection terminal 12 of the light-emitting unit 1, respectively. The optical lens 4 is composed of a silicone material, and the optical lens 4 is an aspheric lens. An aspheric lens refers to a lens whose curvature from the center to the edge changes continuously, and the curvature of the surface is inconsistent at different places. The light-emitting unit 1 includes a flip-chip structure chip or a face-up structure chip.

[0034] In one embodiment, the optical lens manufacturing process includes:

[0035] The split lens structure (split processing technology) uses polycarbonate (PC) or polymethyl methacrylate (PMMA) plastic with a refractive index range of 1.49-1.59. The lens elements are individually molded using an injection molding machine and then bonded to the surface of the LED assembly using UV-curable adhesive or epoxy resin. In this embodiment, the optical lens 4 is non-contactly mounted to the light-emitting unit 1, forming a mechanically fixed but optically isolated structure. The optical lens 4 spans above the light-emitting unit 1 to form a suspended cavity, with the cavity height (i.e., the distance between the inner surface of the lens and the light-emitting unit) controlled to be greater than 1mm. The conductive components (including the first conductive component 2 and the second conductive component 3) are bonded to the inner wall of the optical lens 4 on the side, with the bottom surface completely exposed.

[0036] The molded integrated structure (molding process) uses liquid silicone rubber (LSR) with a refractive index of 1.41-1.53 ​​and a temperature resistance range of -40°C to 200°C. The LED assembly is placed in the mold and directly injection molded to encapsulate it, achieving an integrated lens-device structure. In this embodiment, the silicone lens completely covers the front and side surfaces of the light-emitting unit 1 and the conductive component. The optical lens 4 is closely bonded to the light-emitting unit 1, with no air gap at the interface. Only the bottom surface of the conductive component is exposed, forming a heat dissipation interface.

[0037] Specifically, the surface height of the first supporting area 21 is greater than the surface height of the first reflecting area 22, and the surface height of the second supporting area 31 is greater than the surface height of the second reflecting area 32. The light emitted by the light-emitting unit 1 is reflected by the first reflecting area 22 and the second reflecting area 32, so that the luminous intensity at the center of the LED device and the luminous intensity on the four sides are more uniform, without the need for secondary optical homogenization treatment.

[0038] In one embodiment, a plurality of connectors 5 are further included, wherein the connectors 5 are respectively connected to the optical lens 4 and the first conductive component 2, and the connectors 5 are respectively connected to the optical lens 4 and the second conductive component 3. The connectors 5 are used to enhance the connection firmness between the optical lens 4 and the first conductive component 2 / the second conductive component 3. The component material of the connectors 5 is mainly plastic or silicone.

[0039] In one embodiment, the light-emitting unit 1 is a front-mounted structure; the light-emitting unit 1 includes a first electrical connection end 11 and a second electrical connection end 12, the first electrical connection end 11 is connected to the first reflection area 22 through a first bonding wire, and the second electrical connection end 12 is connected to the second reflection area 32 through a second bonding wire.

[0040] Specifically, when the light-emitting unit 1 is in a face-up structure, the first electrical connection end 11 and the second electrical connection end 12 of the light-emitting unit 1 (for example, an LED chip) face upward, the first bonding wire is a metal conductive wire, and the first electrical connection end 11 is connected to the first reflective area 22 by welding the first bonding wire. The second bonding wire is a metal conductive wire, and the second electrical connection end 12 is connected to the second reflective area 32 by welding the second bonding wire.

[0041] Furthermore, when the light emitting unit 1 is in a face-mounted structure, the light emitting unit 1 is connected to the first carrying area 21 via a first connecting medium, and the light emitting unit 1 is connected to the second carrying area 31 via a first connecting medium.

[0042] Specifically, the first connecting medium is a heat-conducting medium, which is tightly fitted between the light-emitting unit 1 and the first conductive component 2 and tightly fitted between the light-emitting unit 1 and the second conductive component 3. The first connecting medium is a heat-conducting glue.

[0043] In another embodiment, the light emitting unit 1 is a flip-chip structure; the light emitting unit 1 includes a third electrical connection end and a fourth electrical connection end, the third electrical connection end is connected to the first supporting area 21 , and the fourth electrical connection end is connected to the second supporting area 31 .

[0044] Specifically, when the light-emitting unit 1 is a flip-chip structure, the projected area of ​​the first supporting area 21 covers the third electrical connection terminal; the projected area of ​​the second supporting area 31 covers the fourth electrical connection terminal. It is understood that the surface area S1 of the first supporting area 21 and the surface area S3 of the third electrical connection terminal satisfy S1 ≥ S3, and the surface area S2 of the second supporting area 31 and the surface area S4 of the fourth electrical connection terminal satisfy S2 ≥ S4. The surface area relationship is achieved in at least one of the following ways: a) the supporting area (including the first supporting area 21 and the second supporting area 31) is rectangular and has a side length greater than or equal to the corresponding side length of the electrical connection terminal (including the third electrical connection terminal and the fourth electrical connection terminal); b) the supporting area is circular and has a diameter greater than or equal to the diameter of the circumscribed circle of the electrode. A supporting area area greater than or equal to the area of ​​the electrical connection terminal ensures uniform current diffusion, avoids excessive local current density, and provides better process tolerance, thereby improving product yield.

[0045] Furthermore, when the light emitting unit 1 is a flip-chip structure, the first electrical connection end 11 is connected to the first supporting area 21 through a second connection medium, and the second electrical connection end 12 is connected to the second supporting area 31 through a second connection medium.

[0046] Specifically, the second connecting medium is a conductive medium, which is tightly fitted between the light emitting unit 1 and the first conductive component 2 and between the light emitting unit 1 and the second conductive component 3. The second connecting medium is any one of silver glue, solder paste or eutectic soldering.

[0047] Furthermore, the first carrying area 21 and the second carrying area 31 are located on the same reference plane.

[0048] Specifically, the coplanar design reduces the required alignment accuracy between the chip electrodes and the carrier area from ±50μm to ±100μm, improving assembly yield by over 20% and eliminating the need for height compensation during assembly. This coplanar design is achieved through the following processes: During stamping of the conductive carrier (comprising the first conductive component 2 and the second conductive component 3), the mold tolerance is controlled to ≤20μm; and the carrier area surface is treated using a flat grinding process.

[0049] Furthermore, the bottom surfaces of the first conductive component 2 and the second conductive component 3 are both flat surfaces.

[0050] Specifically, the flat bottom surface can achieve full contact heat conduction with the heat sink, eliminating air gaps. The flat bottom surface makes the stress distribution of the welding / adhesive layer uniform, which is conducive to the bottom surfaces of the first conductive component 2 and the second conductive component 3 being firmly welded to the circuit board.

[0051] Furthermore, the surface of the first reflective area 22 is smoothed and metallized.

[0052] In this embodiment, the first conductive component 2 is made of copper metal, and the surface of the first reflective area 22 is electroplated with silver to improve the reflectivity, wherein the light reflectivity of the surface of the electroplated silver with a thickness of 1-3 μm is greater than 95%. The electroplated silver treatment can also enhance the corrosion resistance and prevent the copper substrate from oxidizing to generate insulating copper oxide.

[0053] Furthermore, the surface of the first reflective area 22 is any one of a flat surface, a concave arc surface or a composite curved surface.

[0054] Specifically, when the surface of the first reflective area 22 is a plane, the first reflective area 22 and the first supporting area 21 form a stepped shape. The first reflective area 22 is used to reflect the light of the light emitting unit 1 to the side of the optical lens 4 .

[0055] Furthermore, the surface of the second conductive component 3 is smoothed by metallization.

[0056] In this embodiment, the second conductive component 3 is made of copper metal, and the surface of the first reflective area 22 is electroplated with silver to improve the reflectivity, wherein the light reflectivity of the surface of the electroplated silver with a thickness of 1-3 μm is greater than 95%. The electroplated silver treatment can also enhance the corrosion resistance and prevent the copper substrate from oxidizing to generate insulating copper oxide.

[0057] Furthermore, the surface of the second reflective area 32 is any one of a flat surface, a concave arc surface or a composite curved surface.

[0058] Specifically, when the surface of the second reflective area 32 is a plane, the second reflective area 32 and the second supporting area 31 form a step shape, and the second reflective area 32 is used to reflect the light of the light emitting unit 1 to the side of the optical lens 4 .

[0059] Furthermore, the optical lens 4 includes at least two free-curved surfaces, and a concave area 6 is formed at the connection between the two free-curved surfaces. The concave area 6 is directly above the light-emitting unit 1 .

[0060] Specifically, the top surface of the optical lens 4 is not a traditional spherical lens design, but a free-form surface design. A free-form surface refers to an optical surface that does not have axial rotational symmetry or translational symmetry constraints. The free-form surface design can disperse and homogenize the light of the light-emitting unit through refraction and total reflection. After the light of the light-emitting unit 1 passes through the optical lens 4, its luminous characteristics no longer follow Lambert's cosine law (I(θ)=Incosθ), that is, when looking at the light-emitting unit 1 from a top-down angle, the light emitted from the center surface of the light-emitting unit 1 will decrease, while the light emitted from the edge surfaces on the four sides will increase, thereby making the light emitted by the light-emitting unit more uniform and softer. The recessed area 6 is provided directly above the light-emitting unit 1 to weaken the light intensity at the center of the light-emitting unit 1, so that the light at the center and surrounding areas of the LED device is more uniform.

[0061] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0062] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0063] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0064] In the present invention, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood broadly. For example, they may refer to connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0065] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0066] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms should not be understood as necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0067] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, to the extent such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to encompass such changes and modifications.

[0068] The above description is a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A uniformly luminous LED device, characterized in that: include: The light-emitting unit is electrically connected to the first conductive component and the second conductive component respectively; The first conductive component is provided with a first supporting area and a first reflecting area, and the first reflecting area has a first height difference relative to the first supporting area; The second conductive component is provided with a second supporting area and a second reflecting area, and the second reflecting area has a second height difference relative to the second supporting area; an optical lens, located above the light-emitting unit, the first conductive component, and the second conductive component, and connected to the first conductive component and the second conductive component; The bottom of the light emitting unit is connected to the first carrying area and the second carrying area respectively; The surfaces of the first reflective area and the second reflective area are smoothed and metallized; The surface of the first reflection area is a composite curved surface, and the surface of the second reflection area is a composite curved surface; The optical lens includes at least two free-curved surfaces, a concave area is formed at the connection between the two free-curved surfaces, and the concave area is directly above the light-emitting unit.

2. The uniformly emitting LED device according to claim 1, characterized in that: The light emitting unit is a normal structure; The light emitting unit includes a first electrical connection end and a second electrical connection end. The first electrical connection end is connected to the first reflective region through a first bonding wire, and the second electrical connection end is connected to the second reflective region through a second bonding wire.

3. The uniformly emitting LED device according to claim 2, characterized in that: The light emitting unit is connected to the first carrying area via a first connecting medium, and the light emitting unit is connected to the second carrying area via a first connecting medium.

4. The uniformly emitting LED device according to claim 1, characterized in that: The light-emitting unit is a flip-chip structure; The light emitting unit includes a third electrical connection end and a fourth electrical connection end. The third electrical connection end is connected to the first carrying area, and the fourth electrical connection end is connected to the second carrying area.

5. The uniformly emitting LED device according to claim 4, characterized in that: The first electrical connection end is connected to the first carrying area via a second connection medium, and the second electrical connection end is connected to the second carrying area via a second connection medium.

6. The uniformly emitting LED device according to any one of claims 1 to 5, characterized in that: The first carrying area and the second carrying area are located in the same reference plane.

7. The uniformly emitting LED device according to any one of claims 1 to 5, characterized in that: The bottom surfaces of the first conductive component and the second conductive component are both flat surfaces.

8. The uniformly emitting LED device according to any one of claims 1 to 5, characterized in that: The smooth metallization treatment includes at least one of electroplating silver, electroplating gold, chemical immersion gold, chemical immersion tin or tin spraying process.

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