Cob lamp strip

Abstract

Disclosed is a COB lamp strip, comprising a flexible substrate and LED chips, the LED chips being CSP / COB flip-chip dies, the CSP / COB flip-chip dies being arranged in the length direction of the flexible substrate and attached to a surface of the flexible substrate, surfaces of the CSP / COB flip-chip dies being coated with a white diffusive encapsulant, and the white diffusive encapsulant being a mixture of translucent viscous liquid silicone rubber and mist type liquid silicone rubber. The lamp strip combines the CSP / COB flip-chip dies and COB encapsulation technology, and the CSP / COB flip-chip dies are directly encapsulated on the flexible substrate, the surfaces thereof being encapsulated with the white diffusive encapsulant, thereby not only improving pressing resistance of products, but also improving the corrosion resistance. The CSP / COB flip-chip dies are directly attached to the flexible substrate, thereby enhancing the heat dissipation performance and improving the service life of products.

Description

COB lamp strip TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of lighting, and in particular to a COB lamp strip. BACKGROUND

[0002] Flexible lamp strips are increasingly favored by people due to their convenient installation, flexible use, and wide application. However, the existing lamp strips have the problems that the light source support is easily damaged during transportation and bending in use, causing dead lamps, and the light source and the solder pad are directly exposed, which is easy to corrode and oxidize. These two problems need to be solved to improve product quality. TECHNICAL PROBLEM

[0003] To solve the technical problems that the light source support is easily damaged during transportation and bending in use, causing dead lamps, and the light source and the solder pad are directly exposed, which is easy to corrode and oxidize, in the prior art, the present disclosure provides a COB lamp strip to solve the above problems. TECHNICAL SOLUTION

[0004] The present disclosure provides a COB lamp strip, which comprises a flexible substrate and an LED chip. The LED chip is a CSP or COB flip-chip, which is arranged along the length direction of the flexible substrate and attached to the surface of the flexible substrate. White encapsulating diffusion glue is coated on the surface of the CSP or COB flip-chip. The white encapsulating diffusion glue is a mixture of semi-transparent viscous liquid silicone and fog-like liquid silicone. By combining the CSP / COB flip-chip with the COB packaging technology, the CSP / COB flip-chip is directly packaged on the flexible substrate, and white diffusion glue is coated on the surface, which not only improves the anti-extrusion properties of the product, but also improves the corrosion resistance.

[0005] In some embodiments, the back surface of the flexible substrate is provided with a back adhesive.

[0006] In some embodiments, the electrode of the CSP or COB flip-chip is welded with the solder pad of the flexible substrate. With this arrangement, good heat conduction effect can be achieved, and the heat dissipation problem caused by high single-point power can be solved.

[0007] In some embodiments, when the LED chip is a CSP flip-chip, white diffusion glue is coated on the surface of the CSP flip-chip. The white diffusion glue is a mixture of semi-transparent viscous liquid silicone and fog-like liquid silicone mixed with nano-scale diffusion materials and then solidified.

[0008] In some embodiments, when the LED chip is a COB flip chip, a layer of yellow fluorescent glue is covered on the surface of the COB flip chip, and then a layer of white diffusion glue is covered. Covering the white diffusion glue not only protects the chip and the pad, improves the oxidation resistance and acid and alkali resistance, but also significantly improves the waterproof effect; at the same time, the light emitting effect can be changed to make the light emitting uniform, and the beam angle can be improved to more than 160 degrees.

[0009] In some embodiments, the weight ratio of the translucent viscous liquid silicone glue to the foggy liquid silicone glue is selected from the range of (1-20): 1.

[0010] In some embodiments, after the translucent viscous liquid silicone glue and the foggy liquid silicone glue are mixed, fluorescent powder and diffusion powder are added, and after gelation at 80°C for 1 hour, the temperature is raised to 170°C for 4 hours for curing and forming.

[0011] In some embodiments, the packaging diffusion glue covers the CSP or COB flip chip and has an arc-shaped structure. With this arrangement, better hydrophobic effect can be achieved.

[0012] In some embodiments, the CSP or COB flip chip is located at the maximum thickness of the arc-shaped structure. Advantages

[0013] A COB lamp strip of the present disclosure combines CSP / COB flip chip and COB packaging technology, directly packages on a flexible substrate, and simultaneously packages white diffusion glue on the surface. This not only improves the anti-extrusion characteristics of the product and improves the corrosion resistance, but also increases the heat dissipation performance and improves the service life of the product because the CSP / COB flip chip is directly attached to the flexible substrate. BRIEF DESCRIPTION OF DRAWINGS

[0014] The accompanying drawings are included to provide a further understanding of embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the description, serve to explain the principles of the present disclosure. Other embodiments and many of the intended advantages of the embodiments will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts.

[0015] FIG. 1 is an exploded view of a COB lamp strip according to one embodiment of the present disclosure;

[0016] FIG. 2 is a light emitting schematic view of a flip chip according to one specific embodiment of the present disclosure;

[0017] FIG. 3 is a cross-sectional view of a flip chip according to one specific embodiment of the present disclosure;

[0018] Figure 4 is a schematic diagram of a flip chip covered with a diffusion glue, according to one specific embodiment of the present disclosure;

[0019] Figure 5 is a structural diagram of a lamp, according to one embodiment of the present disclosure. Embodiments of the present invention

[0020] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration illustrative embodiments in which the disclosure can be practiced. For purposes of explanation and illustration, directional terms are used with reference to the orientation of the described figures. Because components of embodiments can be positioned in a number of orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments can be utilized and logical changes can be made without departing from the scope of the present disclosure. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present disclosure is defined by the appended claims.

[0021] A COB lamp strip according to an embodiment of the present disclosure. Figure 1 shows an exploded view of a COB lamp strip according to an embodiment of the present disclosure. As shown in Figure 1, the COB lamp strip includes a flexible substrate 1, LED chips 2, encapsulation diffusion glue 3 (which includes a multi-layer structure, the outermost layer of which is set to white, gray or other colors according to different requirements), and back glue 4. The LED chips 2 are directly attached to the flexible substrate 1 and are arranged uniformly along the length direction of the flexible substrate 1. The encapsulation diffusion glue 3 (which includes a multi-layer structure, the outermost layer of which is set to white, gray or other colors according to different requirements) covers the surface of the LED chips 2, plays a waterproof role for the chips, and can change the light emission effect, making the light emission more uniform. The back glue 4 is disposed on the back of the flexible substrate 1.

[0022] In one specific embodiment of the present disclosure, the LED chips 2 adopt CSP / COB flip chips, which can achieve five-sided light emission. As shown in Figure 2, which is a light emission schematic diagram of a flip chip according to one specific embodiment of the present disclosure, the flip chip can achieve light emission on all five sides except the side connected to the substrate. The use of CSP / COB flip chips in the encapsulation process reduces the phenomenon of chip damage caused by repeated twisting and bending during transportation and use of traditional lamp strips using large chips such as 3030 and 2835.

[0023] Figure 3 is a cross-sectional view of a portion of the inverted small chip according to one specific embodiment of the present disclosure, as shown in Figure 3, the electrodes of the inverted small chip are directly welded with the pads of the flexible substrate 1 through the welding copper foil, thus having good heat conduction effect, solving the heat dissipation problem of high single-point power. The adjacent inverted small chips are connected through the copper foil connecting lines, the thickness of the welding copper foil is greater than that of the copper foil connecting lines, and there is a certain thickness difference between the thickness of the copper foil at the bottom of the light source and the thickness of the copper foil between the light sources. Increasing the thickness of the welding copper foil at the bottom of the light source can improve the reliability of welding and improve the heat dissipation performance, and the thinner copper foil thickness between the light sources is beneficial to improve the bending performance, whether the bending R angle or the bending frequency is increased by 3-5 times.

[0024] In some specific embodiments, for CSP inverted small chips, the packaging diffusion glue 3 (which includes a multi-layer structure, and the outermost layer is set to white, gray or other colors according to different needs) is covered with white diffusion glue on its surface. Specifically, the white diffusion glue is mixed and solidified by mixing a certain proportion of translucent viscous silica gel and fog liquid silica gel, and adding a certain amount of nanoscale diffusion material as needed.

[0025] In some specific embodiments, for COB inverted small chips, the packaging diffusion glue 3 (which includes a multi-layer structure, and the outermost layer is set to white, gray or other colors according to different needs) includes a layer of yellow fluorescent glue first covered on its surface, and then a layer of white diffusion glue. Covering the white diffusion glue not only protects the chip and the pad, improves the oxidation resistance, and improves the acid and alkali resistance, but also significantly improves the waterproof effect, and can change the light output effect to make the light output uniform, and the beam angle can be increased to more than 160 degrees.

[0026] In some specific embodiments, the white silica gel has a main chain structure of silicon-oxygen (Si-O) bond. It is divided into two groups A and B, group A is translucent viscous liquid, and group B is fog liquid. The glue is mixed in a weight ratio of A:B=(1-20):1, and fluorescent powder and diffusion powder are added as needed, and then stirred uniformly. First, bake at 80°C for 1 hour, and then increase the temperature to 170°C and bake for 4 hours to solidify and form.

[0027] Figure 4 shows a schematic diagram of an inverted small chip covered with diffusion glue according to one specific embodiment of the present disclosure, as shown in Figure 4, the packaging diffusion glue 3 (which includes a multi-layer structure, and the outermost layer is set to white, gray or other colors according to different needs) is in a circular arc structure, which is a hydrophobic material. The hydrophobic material can be made of silicone glue with a hydrophobic agent and is a transparent product that does not affect the light output effect. The waterproof glue is dropped into a certain arc by equipment gravity, thus having good hydrophobic effect. Preferably, the CSP or COB inverted small chip is located at the maximum thickness of the middle of the circular arc structure, and the overall light output effect and hydrophobic effect are better.

[0028] The COB lamp strip of the present disclosure can not only be used alone, but also be installed in various types of materials. As shown in the lamp structure diagram according to one embodiment of the present disclosure in FIG. 5, the lamp strip of the foregoing embodiment can be placed in an aluminum profile 5, both ends of which are capped by end covers 7, and the lamp strip is covered by a diffusion cover 6. The lamp strip can also be extruded and coated to form various shapes, and can be used as a light source of a lamp alone, having the characteristics of convenient installation and strong replaceability.

[0029] Obviously, various modifications and changes can be made to the embodiments of the present disclosure by those skilled in the art without departing from the spirit and scope of the present disclosure. In this way, the present disclosure also aims to cover these modifications and changes if they are within the scope of the claims of the present disclosure and their equivalents. The word "comprising" does not exclude the presence of other elements or steps not listed in the claims. The simple fact that certain measures are recited in mutually different dependent claims does not mean that combinations of these measures cannot be used to advantage. Any reference signs in the claims should not be considered as limiting the scope.

Claims

1. A COB light strip, characterized in that, The LED chip is a CSP or COB flip chip, which is arranged on the surface of the flexible substrate along the length direction of the flexible substrate, and a white packaging diffusion glue is coated on the surface of the CSP or COB flip chip, wherein the white packaging diffusion glue is a mixture of semi-transparent viscous liquid silicone and fog liquid silicone.

2. The COB lamp strip according to claim 1, characterized in that, The back surface of the flexible substrate is provided with a back adhesive.

3. The COB lamp strip of claim 1, wherein, The electrode of the CSP or COB flip chip is welded with the pad of the flexible substrate.

4. The COB lamp strip of claim 1, wherein, When the LED chip is a CSP flip chip, a white diffusion glue is coated on the surface of the CSP flip chip, wherein the white diffusion glue is a mixture of semi-transparent viscous liquid silicone and fog liquid silicone and nano-scale diffusion materials.

5. The COB lamp strip of claim 1, wherein, When the LED chip is a COB flip chip, a layer of yellow fluorescent glue is covered on the surface of the COB flip chip, and then a layer of white diffusion glue is covered.

6. The COB lamp strip of claim 1, wherein, The weight ratio of the semi-transparent viscous liquid silicone to the fog liquid silicone is in the range of (1-20):

1.

7. The COB lamp strip of claim 6, wherein, After the semi-transparent viscous liquid silicone and the fog liquid silicone are mixed, fluorescent powder and diffusion powder are added, and after gelation at 80℃ for 1 hour, the temperature is raised to 170℃ for 4 hours for solidification and molding.

8. The COB lamp strip of claim 1, wherein, The packaging diffusion glue covers the CSP or COB flip chip and has an arc structure.

9. The COB lamp strip of claim 8, wherein, The CSP or COB flip chip is located at the maximum thickness of the arc structure.

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