Flexible LED light strip

Abstract

This product provides a flexible LED light tape that allows users to cut the light tape at any desired location, ensuring that the remaining portion illuminates normally without creating any dark areas. [Solution] The flexible LED light tape comprises a flexible circuit board, at least two LED chips 20, 30, and an integrated encapsulant. The flexible circuit board includes a surface insulating layer 101, a back insulating layer 102, and at least two conductive circuit layers 103, 105, 107 and at least one intermediate insulating layer, and any two conductive circuit layers separated by the intermediate insulating layer are electrically connected by conductive via holes penetrating the intermediate insulating layer. The upper LED chip 20 is positioned on the upper surface of the flexible circuit board and electrically connected to the uppermost conductive circuit layer, and the lower LED chip 30 is positioned on the lower surface of the flexible circuit board and electrically connected to the lowermost conductive circuit layer. Furthermore, the light emission directions of the upper and lower LED chips are arranged to be opposite to each other or to form a predetermined angle. The integrated encapsulant encloses the flexible circuit board and the LED chips. This light tape constructs a circuit board structure that enables three-dimensional wiring.

Description

Technical Field

[0001] The present invention belongs to lighting devices, and particularly relates to a flexible LED light tape.

Background Art

[0002] Many of the conventional flexible LED light tapes adopt a configuration in which LED light-emitting elements are arranged only on one side. Therefore, the light-emitting angle is usually limited to a lateral range of about 120°, and there are obvious lighting dead angles, and there is a problem that it cannot meet the requirements of applications that require uniform light emission over the entire range. To improve this problem, in the prior art, several designs related to double-sided light-emitting LED light tapes have been proposed.

[0003] For example, there is a configuration in which LED light-emitting elements are mounted on both the front and back surfaces of a single-layer flexible printed circuit board (FPC). However, due to the wiring capacity limitation of the single-layer FPC, the LEDs on both the front and back surfaces can usually be connected only in a simple parallel connection or an overall series connection method. Such a circuit configuration has significant drawbacks. That is, when the user cuts the LED light tape at a location other than the predetermined cut position, all the LEDs after the cut point will go out due to a circuit break, and a non-light-emitting (dark zone) will be formed. This significantly limits the flexibility for the user to freely cut according to the actual installation length, causing inconveniences such as material waste and lighting discontinuity.

[0004] In addition, conventional flexible light tapes generally do not have a sufficient support structure inside their sealing bodies due to overemphasis on flexibility. Therefore, when installing the light tape, it is difficult to bend it into a specific shape such as an arc shape or a wave shape and maintain that shape. Furthermore, the tensile strength is also low, and there is a problem that it is easily damaged during the pulling process during laying.

Summary of the Invention

Problems to be Solved by the Invention

[0005] This invention aims to solve at least one of the technical problems present in the prior art and provides a flexible LED light tape. [Means for solving the problem]

[0006] A flexible LED light tape comprises a flexible circuit board, at least two LED chips, and an integrated encapsulant. The flexible circuit board has a multilayer structure and includes a top surface insulating layer, a bottom back insulating layer, and at least two conductive circuit layers and at least one intermediate insulating layer alternately arranged between the surface insulating layer and the back insulating layer, the back insulating layer being directly provided on one of the conductive circuit layers. Any two conductive circuit layers separated by the intermediate insulating layer are electrically connected by conductive via holes penetrating the intermediate insulating layer. The upper LED chip is located on the top surface of the flexible circuit board and is electrically connected to the uppermost conductive circuit layer. The lower LED chip is located on the bottom surface of the flexible circuit board and is electrically connected to the bottommost conductive circuit layer. Furthermore, the light-emitting directions of the upper and lower LED chips are arranged to be opposite to each other or to form a predetermined angle. The integrated encapsulant is formed of a translucent encapsulant material and encloses the flexible circuit board and the LED chips.

[0007] Preferably, the surface insulating layer is a white solder resist film.

[0008] Preferably, the conductive circuit layer is a copper foil layer.

[0009] Preferably, the intermediate insulating layer is a polyimide layer.

[0010] Preferably, the holes and end faces of the conductive via holes are coated with a metallic tin layer.

[0011] Preferably, the light-transmitting sealing material is an optical-grade liquid silicone.

[0012] Preferably, the back insulating layer is a white solder resist film. [Effects of the Invention]

[0013] Compared to conventional technology, the beneficial effects of this invention are as follows:

[0014] In the LED light tape of this invention, the upper LED chips are placed on the upper surface of a flexible circuit board, the lower LED chips are placed on the lower surface, and the light emission directions are set to opposite directions or at a predetermined angle. Furthermore, the entire structure is encased in a translucent encapsulant, resulting in uniform light emission from the entire circumference of the light tape. This completely eliminates the approximately 120° light emission angle limitation of conventional single-sided arrangements, achieving uniform 360° illumination without visual blind spots. Additionally, by employing a multilayer laminated structure and interlayer connections via conductive via holes penetrating the insulating layer, a circuit board structure enabling three-dimensional wiring is constructed. As a result, even if the light tape is cut at any desired location by the user, the remaining portion after cutting will all light up normally, eliminating the occurrence of dark zones. This significantly improves the practicality and flexibility of the product. [Brief explanation of the drawing]

[0015] To more clearly explain the technical solution in this invention, the drawings used in the embodiments are briefly described below. Note that the drawings described below relate to only some embodiments of this invention, and those skilled in the art can derive other drawings from these without requiring any creative effort.

[0016] [Figure 1] This is a schematic diagram showing the first structure of the flexible LED light tape according to this application. [Figure 2] This is a schematic diagram showing the structure of the flexible circuit board related to this application. [Figure 3]This is a schematic diagram showing the curved state of the flexible LED light tape according to this application. [Figure 4] This is a schematic diagram showing a second structure of the flexible LED light tape according to this application. [Figure 5] This is a cross-sectional view of the flexible LED light tape relating to this application. [Modes for carrying out the invention]

[0017] This section describes specific embodiments of the present invention in detail. Preferred embodiments of the present invention are shown in the drawings. In the embodiments shown in the drawings, the same or similar reference numerals indicate the same or similar components, or components having the same or similar functions.

[0018] The orientation shown in the drawings does not limit the scope of protection of this invention, but is merely a reference illustration for understanding preferred embodiments. The positional relationships of the illustrated product parts can be changed, and the number of parts can be increased or decreased, or the structure can be simplified.

[0019] In this specification, "connections" or "connection relationships" between components shown in the drawings should be understood as encompassing fixed connections, detachable connections, or integral connections. These connections may be direct or indirect, via intermediate members. Those skilled in the art can select and substitute various appropriate connection methods, such as screw connections, crimping, soldering, mating, push-in, or other suitable connection methods, depending on the specific configuration and operating environment.

[0020] Terms indicating directions such as "up", "down", "left", "right", "above", "below", etc. described in the specification, as well as the orientations of each part shown in the drawings, are used for the sake of convenience in explanation and do not limit the structure of the present invention. Each member may be in direct contact with each other, or may be in contact through other components therebetween. "Above" does not necessarily mean directly above in the vertical direction, and also includes cases where it refers to being diagonally above or at a position higher than other members. The same interpretation can be made for other terms indicating directions.

[0021] For the materials of the members having the physical shapes shown in the specification and drawings, metal materials, non-metal materials, or other composite materials can be used. Regarding the manufacture of the members having physical shapes, various machining methods such as press working, forging, casting, wire cutting, laser cutting, injection molding, numerical control cutting (NC milling), 3D printing, machining, etc. can be adopted. A person skilled in the art can appropriately select or combine these materials and machining methods according to requirements such as processing conditions, cost, and accuracy. Note that the present invention is not limited to the above materials and machining methods.

[0022] An LED light strip with flexibility, comprising a flexible circuit board 1, at least two LED chips, and an integrated encapsulation body 3. The flexible circuit board 1 has a multi-layer laminated structure, including a surface insulation layer 101 located on the upper part, a back insulation layer 102 located on the lower part, and at least two conductive circuit layers and at least one intermediate insulation layer alternately arranged between the surface insulation layer 101 and the back insulation layer 102. Among them, the back insulation layer 102 is directly provided on one of the conductive circuit layers. Between any two conductive circuit layers separated by the intermediate insulation layer, they are electrically connected by a conductive via hole 100 penetrating the intermediate insulation layer. The upper-layer LED chip is arranged on the upper surface of the flexible circuit board 1 and is electrically connected to the conductive circuit layer located on the uppermost layer. The lower-layer LED chip is arranged on the lower surface of the flexible circuit board 1 and is electrically connected to the conductive circuit layer located on the lowermost layer. And the light-emitting directions of the upper-layer and lower-layer LED chips are arranged in opposite directions to each other or form a predetermined angle. The integrated encapsulation body 3 is formed of a light-transmitting encapsulation material and encapsulates the flexible circuit board 1 and the LED chips.

[0023] Furthermore, the surface insulation layer 101 is a white solder resist film.

[0024] Furthermore, the conductive circuit layer is a copper foil layer.

[0025] Furthermore, the intermediate insulation layer is a polyimide layer.

[0026] Furthermore, the hole wall and end face of the conductive via hole 100 are coated with a metal tin layer.

[0027] Furthermore, the light-transmitting encapsulation material is an optical-grade liquid silicone.

[0028] Furthermore, the back insulation layer 102 is a white solder resist film.

[0029] The operating principle of the present invention is as follows.

[0030] In Example 1, the light tape comprises a flexible circuit board 1, a first LED chip 20, a second LED chip 30, and an integrated encapsulant 3. The flexible circuit board 1 has a multilayer structure. Specifically, from top to bottom, a white solder resist film as the surface insulating layer 101, a copper foil layer as the first conductive circuit layer 103, a polyimide layer as the first insulating layer 104, a copper foil layer as the second conductive circuit layer 105, a polyimide layer as the second insulating layer 106, a copper foil layer as the third conductive circuit layer 107, a polyimide layer as the third insulating layer 108, a copper foil layer as the fourth conductive circuit layer 109, and a white solder resist film as the back insulating layer 102 are sequentially laminated.

[0031] The first conductive circuit layer 103, the second conductive circuit layer 105, the third conductive circuit layer 107, and the fourth conductive circuit layer 109 are electrically connected by conductive via holes 100 that penetrate the corresponding polyimide insulating layers.

[0032] The holes and end faces of the conductive via holes 100 are coated with a metallic tin layer by tin plating, thereby ensuring the reliability of the connection.

[0033] The first LED chip 20 is soldered onto the first conductive circuit layer 103, and the second LED chip 30 is soldered to the side of the back insulating layer 102 opposite to the fourth conductive circuit layer 109.

[0034] The first LED chip 20 and the second LED chip 30 are positioned back-to-back, their optical axes are parallel, and their light-emitting directions are opposite to each other. The circuit on the flexible circuit board 1 is configured as a plurality of series-connected circuit units, and each circuit unit includes the first LED chip 20, the second LED chip 30, and a current-limiting resistor (not shown) provided in the circuit. This realizes a function in which cutting at any position does not affect the operation of subsequent units.

[0035] The specific operating principle is as follows:

[0036] The key to achieving the function of "not generating dark zones even when arbitrarily cut" is to connect the first LED chip 20, the second LED chip 30, and the current-limiting resistor R by three-dimensional wiring inside the multilayer flexible circuit board 1 to form a single basic light-emitting unit.

[0037] Specifically, the current-limiting resistor R is soldered as an independent surface-mount component to the surface (e.g., the upper or lower layer) of the multilayer flexible circuit board 1.

[0038] The current-limiting resistor R is connected in series with the first LED chip 20 and the second LED chip 30 via conductive via holes 100 that penetrate the conductive circuit layer and insulating layer inside the flexible circuit board 1, so that the current flow forms a three-dimensional closed circuit.

[0039] The three-dimensional circuit, composed of the conductive via hole 100, the conductive circuits of each layer, the surface-mounted LED chip, and the current-limiting resistor R, forms a basic light-emitting unit consisting of a first LED chip 20 on the upper surface, a second LED chip 30 on the lower surface, and a current-limiting resistor. The entire light strip is constructed by connecting multiple such basic light-emitting units in series along its longitudinal direction.

[0040] The first LED chip 20, which is arranged on the upper surface of the flexible circuit board 1, consists of multiple LED package elements (i.e., multiple light-emitting elements) arranged at predetermined intervals along the longitudinal direction of the light tape, fixed on the surface insulating layer 101, and electrically connected to form a single assembly.

[0041] Similarly, the second LED chip 30, located on the lower surface of the flexible circuit board 1, also consists of multiple LED package elements arranged at predetermined intervals along the longitudinal direction, fixed on the back insulating layer 102, and electrically connected to form another assembly. The first LED chip 20 and the second LED chip 30 are positioned back-to-back spatially.

[0042] When a user cuts along a pre-set cutting position, the only thing that is interrupted by the cutting operation is the horizontal power connection line between adjacent basic light-emitting units connected in series.

[0043] In any complete basic light-emitting unit that remains uncut, the inherent three-dimensional current circuit formed within it is maintained as a closed circuit.

[0044] Therefore, the power supply current continues to flow normally through all the retained basic light-emitting units, allowing the first LED chip 20 on the top surface and the second LED chip 30 on the bottom surface of each unit to emit light normally. This achieves the practical effect of "no dark zones occurring even when arbitrarily disconnected."

[0045] Based on the above technical plan, the integrated sealant 3 is formed from optical-grade liquid silicone. This liquid silicone has high light transmittance and excellent diffusivity, optimizing light extraction and diffusion effects. In the manufacturing process, the assembled flexible circuit board 1, along with the first LED chip 20, second LED chip 30, current-limiting resistors, and other electronic components mounted on it, are placed in a molding die. Optical-grade liquid silicone is then injected into the mold cavity to completely immerse and encase all electronic components and the circuit board. Subsequently, the silicone is cured by heating to form an integrated encapsulated body 3 with a dense structure that matches the shape of the mold.

[0046] The cured encapsulant completely and tightly encloses the flexible circuit board 1, the first LED chip 20, the second LED chip 30, and all other electronic components, forming a continuous, seamless, transparent, integrated protective structure. This structure provides excellent physical protection and electrical insulation, and, thanks to its optically designed material properties (specific refractive index, transmittance, and haze value), it allows the point-like, intense light emitted from the LED chips to be sufficiently scattered, diffused, and mixed within the encapsulant, enabling uniform, soft, and visually uniform 360° omnidirectional light emission from the entire surface of the encapsulant.

[0047] In the LED light tape of this invention, the upper layer of LED chips is placed on the upper surface of a flexible circuit board, the lower layer of LED chips is placed on the lower surface, and the light emission directions are set to opposite directions or at a predetermined angle, and the entire structure is covered with a light-transmitting encapsulant. As a result, light is uniformly diffused and emitted from the entire circumference of the light tape. This completely eliminates the approximately 120° light emission angle limitation of conventional single-sided arrangement methods, and achieves uniform illumination in all 360° directions without any visual blind spots.

[0048] Furthermore, by employing a multilayer laminated structure and interlayer connections using conductive via holes 100 that penetrate the insulating layer, a circuit board structure capable of three-dimensional wiring is constructed. As a result, even if the light tape is cut at any desired location by the user, the remaining portion after cutting will all light up normally, and no dark areas will occur, significantly improving the practicality and flexibility of the product.

[0049] Although the present invention has been described in detail above with reference to examples, various changes or modifications can be made based on this disclosure, as will be obvious to those skilled in the art, as long as they do not depart from the principles and spirit of the present invention. Therefore, the detailed description of the examples in this disclosure is for illustrative purposes only and does not limit the present invention, and the scope of protection of the present invention is determined by the content of the claims. [Explanation of Symbols]

[0050] 1 Flexible circuit board 3 Integrated sealing body 20 First LED Chip 30 Second LED chip 100 conductive via holes 101 Surface insulating layer 102 Rear insulating layer 103 First conductive circuit layer 104 First insulating layer 105 Second conductive circuit layer 106 Second insulating layer 107 Third conductive circuit layer 108 Third insulating layer 109 Fourth conductive loop layer

Claims

1. A flexible LED light tape, The device comprises a flexible circuit board (1), at least two LED chips, and an integrated encapsulant (3), The flexible circuit board (1) has a multilayer laminated structure and includes a surface insulating layer (101) located at the top, a back insulating layer (102) located at the bottom, and at least two conductive circuit layers and at least one intermediate insulating layer alternately arranged between the surface insulating layer (101) and the back insulating layer (102). The aforementioned back insulating layer (102) is provided directly on one of the conductive circuit layers. Any two conductive circuit layers separated by an intermediate insulating layer are electrically connected by conductive via holes (100) that penetrate the intermediate insulating layer. The upper LED chip is positioned on the upper surface of the flexible circuit board (1) and is electrically connected to the conductive circuit layer located in the uppermost layer. The lower LED chip is positioned on the lower surface of the flexible circuit board (1) and is electrically connected to the conductive circuit layer located at the bottom layer. Furthermore, the light-emitting directions of the upper and lower LED chips are arranged to be opposite to each other or to form a predetermined angle. The integrated encapsulant (3) is formed of a light-transmitting encapsulant material and encloses the flexible circuit board (1) and the LED chip. A flexible LED light strip characterized by the following features.

2. The aforementioned surface insulating layer (101) is a white solder resist film. The flexible LED light tape according to feature 1.

3. The conductive circuit layer is a copper foil layer. The flexible LED light tape according to feature 1.

4. The aforementioned intermediate insulating layer is a polyimide layer. The flexible LED light tape according to feature 1.

5. The holes and end faces of the conductive via holes (100) are coated with a metallic tin layer. The flexible LED light tape according to feature 1.

6. The light-transmitting sealing material is an optical-grade liquid silicone. The flexible LED light tape according to feature 1.

7. The back insulating layer (102) is a white solder resist film. The flexible LED light tape according to feature 1.

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