Constant-current COB lamp strip

Abstract

The utility model belongs to the technical field of lighting devices, and provides a constant-current COB lamp strip which comprises a substrate, an LED chip and a constant-current chip. Wherein a plurality of LED chips are arranged; a conductive circuit with a plurality of welding spots is processed on the surface of the substrate, and the welding spots are coated with solid crystal glue; the electrodes of the LED chip and the constant current chip are in direct contact with the welding spots; the LED chip, the constant current chip and the substrate form an electrical path of the COB lamp strip through solid crystal bonding. According to the invention, the constant-current chip is directly die-bonded on the substrate to form an electrical path with the LED chip, so that the processing and manufacturing process that the traditional constant-current chip needs to be packaged together with an integrated circuit in advance during installation is saved, and the die bonding process can ensure the stable electrical connection between the constant-current chip and the substrate, reduce the contact resistance and improve the reliability of the LED chip. And meanwhile, the die bonding glue can help the constant-current chip to effectively conduct heat to the substrate and dissipate the heat when the constant-current chip works, so that the heat dissipation effect is good.

Description

Technical Field

[0001] The present application belongs to the technical field of lighting devices, and specifically relates to a constant current COB light strip. Background Art

[0002] COB light strips are an emerging lighting component product based on the semiconductor light-emitting properties of LED chips. They tightly package multiple LED chips on a single substrate. When current flows through these chips, electrons gain energy in the semiconductor material and transition from a low energy level to a high energy level. When electrons transition back from a high energy level to a low energy level, the excess energy is released as photons, generating light. The brightness of each LED chip depends primarily on the current passing through it. To ensure stable COB light strip lighting, a constant current chip is typically incorporated into the lighting circuit. This chip continuously adjusts the output voltage based on the set current value, ensuring that the current flowing through each LED chip remains constant.

[0003] The existing constant current chip mounting structure directly encapsulates the constant current chip in an integrated circuit package, which is then attached to a substrate. However, encapsulating the constant current chip in an integrated circuit requires high-precision equipment and complex manufacturing processes. Failure of the constant current chip may require replacement of the entire integrated circuit, resulting in high manufacturing and maintenance costs. Furthermore, the constant current chip generates heat during operation, and encapsulating it inside the integrated circuit lengthens the heat dissipation path, resulting in poor heat dissipation. Furthermore, the signal transmission path between the internal and external circuits of the integrated circuit is relatively complex and susceptible to electromagnetic interference, leading to signal distortion or increased bit error rates. Summary of the Invention

[0004] In order to solve the problems of electrical performance being easily interfered with and heat dissipation being poor in the existing COB light strip constant current chip mounting structure, the present application provides a constant current COB light strip.

[0005] In one solution, a constant current COB light strip includes a substrate, an LED chip, and a constant current chip;

[0006] There are several LED chips; the surface of the substrate is processed with a conductive circuit with several solder joints, and the solder joints are coated with a die-bonding glue;

[0007] The electrodes of the LED chip and the constant current chip are in direct contact with the solder joints; the LED chip, the constant current chip and the substrate are bonded together through die bonding to form the electrical path of the COB light strip.

[0008] In one aspect, the electrical pathway can be a high voltage circuit or a low voltage circuit.

[0009] In one solution, the constant current COB light strip also includes a rectifier chip;

[0010] The rectifier chip is connected in series on the electrical path, and the electrodes of the rectifier chip are in direct contact with the welding points.

[0011] In one solution, the substrate is divided into a plurality of shearable units along the length direction, and each shearable unit is provided with a constant current chip, a rectifier chip and a plurality of LED chips.

[0012] In one solution, the die-bonding adhesive can be replaced with printed solder paste, and the electrodes of the LED chip, constant current chip and / or rectifier chip are fixed by reflow soldering after contacting the solder joints.

[0013] In one solution, the constant current COB light strip also includes encapsulating silicone;

[0014] The encapsulating silica gel is applied on the substrate, and the encapsulating silica gel completely covers each functional chip on the substrate.

[0015] In one solution, the LED chip can be replaced with a CSP lamp bead.

[0016] Beneficial effects of this application:

[0017] This application directly bonds the constant current chip to the substrate to form an electrical path with the LED chip, saving the traditional constant current chip installation processing and manufacturing process that requires it to be packaged with the integrated circuit in advance. The bonding process can ensure the stable electrical connection between the constant current chip and the substrate, reduce contact resistance, and reduce loss and distortion in the signal transmission process. At the same time, the bonding glue can help the constant current chip effectively conduct heat to the substrate and dissipate it during operation, resulting in good heat dissipation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0019] Figure 1 This is a circuit diagram of a high-voltage constant-current COB light strip in one embodiment of the present application;

[0020] Figure 2 This is a circuit diagram of a low-voltage constant-current COB light strip in one embodiment of the present application;

[0021] Figure 3 This is a circuit diagram of a driver-free high-voltage constant-current COB light strip in one embodiment of the present application;

[0022] Reference numerals in the figures:

[0023] 1. Substrate; 2. LED chip; 3. Constant current chip; 4. Rectifier chip;

[0024] H is the shear line of the shearable unit of the substrate. DETAILED DESCRIPTION

[0025] The specific embodiments of the present application are further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present application, but are not intended to limit the scope of the present application. Similarly, the following examples are only some embodiments of the present application and not all embodiments. All other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of this application.

[0026] In the description of the present application, 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", "axial", "radial", "circumferential" and the like 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 application and simplifying the description, and do not indicate or imply 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 a limitation on the present application.

[0027] 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 defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0028] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0029] In this application, the terms "one embodiment", "some embodiments", "examples", "specific examples", 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 application. In this specification, the schematic representations of the above terms do not necessarily refer 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 and the features of different embodiments or examples without contradiction.

[0030] To address the issues of electrical performance being susceptible to interference and poor heat dissipation in existing COB light strip constant current chip mounting structures, this application provides a constant current COB light strip. Specific embodiments are as follows:

[0031] In one embodiment, see Figure 1 and Figure 2 The constant current COB light strip includes a substrate 1, an LED chip 2 and a constant current chip 3.

[0032] In this embodiment, a plurality of LED chips 2 are provided; a conductive circuit having a plurality of solder joints is processed on the surface of the substrate 1, and the solder joints are coated with a die-bonding adhesive; the electrodes of the LED chip 2 and the constant current chip 3 are in direct contact with the solder joints; the LED chip 2, the constant current chip 3 and the substrate 1 are bonded together through die-bonding to form an electrical path for the COB light strip.

[0033] Among them, the processing of conductive paths on the substrate 1 can be achieved by metal-based printing or photolithography. Metal-based printing uses silver paste or copper paste as a conductive material to be printed on the substrate 1 and then dried or sintered to solidify the conductive path, which has good conductivity and mechanical strength. Photolithography uses photolithography technology to transfer the designed circuit pattern to the substrate 1. Through the exposure and development of the photoresist, the unnecessary metal layer is removed, leaving the required conductive path. The die-bonding glue usually uses conductive silver glue. The conductive silver glue has good conductivity and adhesion. After being heated and cured, it can firmly fix the constant current chip 3 and the LED chip 2 on the substrate 1 and ensure the electrical connection between the constant current chip 3 and the LED chip 2 and the substrate 1.

[0034] In this embodiment, the constant current chip 3 is an integrated circuit capable of maintaining a constant output current within a certain voltage range. It automatically adjusts the output current through internal feedback control mechanisms, ensuring that the current flowing through each LED chip 2 remains constant, ensuring stable brightness and extending the lifespan of the LED chips 2.

[0035] In this embodiment, the LED chip 2 and the constant current chip 3 are placed on the substrate 1 using a die bonder. The die bonder evenly places the LED chip 2 and the constant current chip 3 on the substrate 1 using a preset arrangement and at an appropriate pressure and speed, ensuring direct contact between the electrodes of the LED chip 2 and the constant current chip 3 and the solder joints while preventing damage or positional shifting of the chips. Compared to traditional integrated circuit packaging methods, the die bonder ensures a stable connection between the LED chip 2 and the constant current chip 3 and the substrate 1 through precise die bonding. The excellent electrical and thermal conductivity of the die bonder improves the performance and efficiency of the circuit and enhances heat dissipation. Furthermore, the direct die bonder fixation method is beneficial for increasing the integration of each chip, achieving miniaturization while ensuring uniform light emission.

[0036] Therefore, the present application saves the traditional processing and manufacturing process of installing the constant current chip 3 by directly bonding the constant current chip 3 to the substrate 1 to form an electrical path with the LED chip 2, and the bonding process can ensure the stability of the electrical connection between the constant current chip 3 and the substrate 1, reduce the contact resistance, and reduce the loss and distortion in the signal transmission process. At the same time, the bonding glue can help the constant current chip 3 effectively conduct heat to the substrate 1 and dissipate it during operation, avoiding interference with the electrical performance of the constant current chip 3 and achieving efficient heat dissipation.

[0037] In one embodiment, based on the above embodiments, the electrical path of the COB light strip formed by die-bonding the LED chip 2 , the constant current chip 3 and the substrate 1 can be a high-voltage circuit or a low-voltage circuit.

[0038] In this embodiment, depending on the different usage scenarios of the constant current COB light strip, light strips of different lengths and powers need to be used for matching. The high-voltage circuit can drive a longer light strip, but due to the high operating voltage, the heat generated per unit length is large, which will limit the service life of the COB light strip; while the low-voltage circuit is limited by the characteristics of DC power supply, the brightness will decrease if the length is too long, but the operating voltage is low, the heat dissipation performance is relatively good, the light loss is small, and the service life is long. Among them, the high-voltage circuit can be installed by connecting the positive pole of each chip to the negative pole of the adjacent chip in sequence; while the installation structure of the low-voltage circuit is relatively complex. For example, the low-voltage circuit can be implemented by connecting two groups of multiple parallel LED chips in series to form a mixed connection circuit. The mixed connection method can not only ensure the consistency of brightness to a certain extent, but also improve the reliability of the system.

[0039] In one embodiment, see Figure 3 The constant current COB light strip further includes a rectifier chip 4; the rectifier chip 4 is connected in series on the electrical path, and the electrode of the rectifier chip 4 is in direct contact with the soldering point.

[0040] The rectifier chip 4 is a semiconductor device that can convert alternating current into direct current, and mainly uses the unidirectional conductivity of the semiconductor to achieve the rectification function.

[0041] In this embodiment, the normal operation of the general LED chip 2 requires a suitable DC power supply. However, the conventional input mains power is 220V AC. This input mains power needs to be converted to DC power, and then stepped down and stabilized to ensure normal and safe illumination of the LED chip 2. Therefore, the traditional COB light strip requires an external driver power supply. However, by directly bonding the rectifier chip 4 to the substrate 1 and connecting it in series with the light-emitting circuit, the input mains power can be converted into a DC power supply suitable for the LED chip 2, making the constant current COB light strip driver-free, thereby forming a driver-free high-voltage constant-current COB light strip or a driver-free low-voltage constant-current COB light strip.

[0042] In one embodiment, the substrate 1 is divided into several cuttable units along its length. Each cuttable unit is equipped with a constant current chip 3, a rectifier chip 4, and several LED chips 2. By dividing the substrate 1 into several cuttable units, the length of the constant current COB light strip can be tailored to suit the actual usage environment while ensuring stable performance of each cuttable unit.

[0043] In one embodiment, the die-bonding adhesive can be replaced with printed solder paste. After the electrodes of the LED chip 2, constant current chip 3, and / or rectifier chip 4 are in contact with the solder joints, they are fixed by reflow soldering. Compared with die-bonding adhesive, printed solder paste has higher thermal and electrical conductivity and higher bonding strength, making it more suitable for use in harsh environments with high temperature and high humidity. However, printed solder paste has high process requirements and requires equipment such as a specialized reflow oven. There are also incompatibilities with some chip and substrate 1 materials. Therefore, the choice between die-bonding adhesive and printed solder paste can be flexibly selected according to the usage environment.

[0044] In one embodiment, based on the aforementioned embodiments, the constant current COB light strip further includes encapsulating silicone. The encapsulating silicone is applied to substrate 1 and completely covers the functional chips on substrate 1. The LED chip 2, constant current chip 3, and rectifier chip 4 are inherently fragile. Encapsulating the chips with a layer of silicone on substrate 1 protects them from external physical impact and chemical corrosion. It also provides good electrical insulation between the chips, ensuring stable and safe operation of the light strip's circuit system.

[0045] In one embodiment, LED chip 2 can be replaced with a CSP lamp bead. CSP lamp beads are chip-scale packaged LED beads with dimensions comparable to or no larger than 20% of the size of LED chip 2. While occupying similar space, CSP lamp beads offer superior optical and heat dissipation performance, enabling long-term stable operation. They also reduce the number of solder joints and connection lines, resulting in higher product reliability. However, CSP lamp beads also have relatively high manufacturing process and material requirements, resulting in high costs and technical barriers, making mass production and application difficult, and they also lack mechanical strength. Therefore, LED chip 2 and CSP lamp beads can be flexibly replaced based on actual production and usage environments.

[0046] The above are only optional embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A constant current COB light strip, comprising a substrate, an LED chip and a constant current chip, characterized in that: The LED chips are provided in plurality; the surface of the substrate is processed with a conductive circuit having a plurality of solder joints, and the solder joints are coated with a die-bonding adhesive; The electrodes of the LED chip and the constant current chip are in direct contact with the solder joints; the LED chip, the constant current chip and the substrate are bonded together to form an electrical path for the COB light strip.

2. The constant current COB light strip according to claim 1, characterized in that: The electrical path may be a high voltage circuit or a low voltage circuit.

3. The constant current COB light strip according to claim 2, characterized in that: Also includes rectifier chip; The rectifier chip is connected in series on the electrical path, and the electrode of the rectifier chip is in direct contact with the welding point.

4. The constant current COB light strip according to claim 3, characterized in that: The substrate is divided into a plurality of shearable units along the length direction, and each shearable unit is provided with a constant current chip, a rectifier chip and a plurality of LED chips.

5. The constant current COB light strip according to claim 4, characterized in that: The die-bonding adhesive can be replaced with printed solder paste, and the electrodes of the LED chip, the constant current chip and / or the rectifier chip are fixed by reflow soldering after contacting the solder joints.

6. The constant current COB light strip according to any one of claims 1 to 5, characterized in that: Also included are encapsulated silicone; The encapsulating silica gel is applied on the substrate, and the encapsulating silica gel completely covers each functional chip on the substrate.

7. The constant current COB light strip according to claim 4, characterized in that: The LED chips can be replaced with CSP lamp beads.

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