COB packaging structure

Abstract

This application discloses a COB packaging structure that solves the technical problem of unstable gold wire in existing technologies. It includes a circuit board assembly, a fixing assembly, a sensor, gold wire adhesive, gold wire, and a first coping adhesive. The fixing assembly covers the circuit board assembly, and the sensor is mounted on the circuit board assembly. The two ends of the gold wire are electrically connected to the sensor and the circuit board assembly, respectively, and the gold wire passes through the gold wire adhesive and the first coping adhesive. The COB packaging structure disclosed in this application improves the reliability and stability of the packaging by adding gold wire adhesive and the fixing assembly, reducing the risk of gold wire breakage or short circuit due to vibration. At the same time, the gold wire adhesive and the fixing assembly also provide additional protection for the sensor, shielding it from external environmental influences. Completely encapsulating the gold wire with gold wire adhesive effectively reduces the risk of module flare caused by gold wire reflection.

Description

Technical Field

[0001] This application belongs to the field of packaging technology, specifically relating to a COB packaging structure. Background Technology

[0002] COB technology is a technique that directly packages electronic components (such as LED chips) onto a printed circuit board (PCBA). COB stands for Chip On Board, a bare-chip mounting technology. In this method, instead of using separate packaging components, the exposed integrated circuit is directly connected to the PCBA surface. Conductive or non-conductive adhesives are used to fix the chip onto the PCBA board (circuit board assembly), and then gold wire bonding technology is used to achieve the electrical connection between the chip and the substrate.

[0003] However, the gold wires between the chip and the substrate in existing systems are typically exposed to the air. Under prolonged operation and high-vibration environments, these gold wires are prone to breakage or short circuits due to vibration, thus affecting the reliability and stability of the package. Furthermore, traditional packaging structures do not provide sufficient protection for the sensor, making it susceptible to external environmental influences. Utility Model Content

[0004] To address the aforementioned technical problems, this application provides a COB packaging structure.

[0005] The technical solution adopted to achieve the purpose of this application is as follows: This utility model discloses a COB packaging structure, including:

[0006] Circuit board assembly;

[0007] A fixing component is provided on the circuit board assembly and together with the circuit board assembly forms a mounting cavity;

[0008] A sensor is mounted on the circuit board assembly, and the sensor is located within the mounting cavity;

[0009] Gold wire adhesive is applied to the sidewall of the sensor and is connected to the circuit board assembly.

[0010] A gold wire, with both ends electrically connected to the sensor and the circuit board assembly respectively, and the end of the gold wire connected to the circuit board assembly passing through the gold wire adhesive, wherein the gold wire is disposed on each sidewall of the sensor where the gold wire adhesive is disposed; and

[0011] The first dam adhesive is disposed on the top of the sensor, and the end of the gold wire connected to the sensor passes through the first dam adhesive.

[0012] In some embodiments, the first dammed adhesive is ring-shaped along the circumference of the sensor.

[0013] In some embodiments, the gold thread adhesive is connected to the first damming adhesive, and the gold thread is threaded through the gold thread adhesive and the first damming adhesive.

[0014] In some embodiments, the height of the gold wire adhesive is greater than the height of the sensor, and the first dam adhesive is connected to the portion of the gold wire adhesive that extends beyond the sensor.

[0015] In some embodiments, the top of the gold thread adhesive is flush with the top of the first dam adhesive.

[0016] In some embodiments, a second dammed adhesive is also included, which is located at the bottom of the gold wire adhesive and on the side of the gold wire adhesive opposite to the sensor, and the second dammed adhesive is ring-shaped along the circumference of the sensor.

[0017] In some embodiments, the second dam adhesive is spaced apart from the sensor.

[0018] In some embodiments, the height of the second dam adhesive is less than the height of the gold thread adhesive.

[0019] In some embodiments, the gold wire adhesive is disposed on three sidewalls of the sensor.

[0020] In some implementations, the sensor is bonded to the circuit board assembly.

[0021] As can be seen from the above technical solution, the COB packaging structure disclosed in this application includes a circuit board assembly, a fixing assembly, a sensor, gold wire adhesive, gold wire, and a first damming adhesive. The fixing assembly covers the circuit board assembly and forms a mounting cavity with the circuit board assembly. The sensor is mounted on the circuit board assembly and is located within the mounting cavity. The gold wire adhesive surrounds the sidewalls of the sensor and is connected to the circuit board assembly; the gold wire adhesive is disposed on at least two consecutive sidewalls of the sensor. The two ends of the gold wire are electrically connected to the sensor and the circuit board assembly, respectively, and the end of the gold wire connected to the circuit board assembly passes through the gold wire adhesive; the gold wire is disposed on each sidewall of the sensor where the gold wire adhesive is disposed. The first damming adhesive is disposed on the top of the sensor, and the end of the gold wire connected to the sensor passes through the first damming adhesive.

[0022] The COB packaging structure disclosed in this application improves the reliability and stability of the packaging by adding gold wire bonding adhesive and fixing components, reducing the risk of gold wire breakage or short circuit due to vibration. Simultaneously, the gold wire bonding adhesive and fixing components also provide additional protection for the sensor, shielding it from external environmental influences. Completely encapsulating the gold wire with gold wire bonding adhesive effectively reduces the risk of module flare caused by gold wire reflection. Attached Figure Description

[0023] To enable those skilled in the art to more clearly understand this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0024] Figure 1 This is a schematic diagram of the COB packaging structure in one or more embodiments of this application;

[0025] Figure 2 for Figure 1 Exploded view of the COB packaging structure;

[0026] Figure 3 for Figure 1 A front cross-sectional view of the COB packaging structure;

[0027] Figure 4 for Figure 1 A schematic diagram showing the positions of the Zhongjin wire adhesive and the first cofferdam adhesive;

[0028] Figure 5 for Figure 1 A schematic diagram showing the connection between the gold wire and the sensor.

[0029] Explanation of reference numerals in the attached figures:

[0030] 100 - Circuit board assembly, 110 - Mounting cavity, 200 - Fixing assembly, 300 - Sensor, 400 - Gold wire adhesive, 500 - Gold wire, 600 - First dam adhesive, 700 - Second dam adhesive. Detailed Implementation

[0031] To enable those skilled in the art to more clearly understand this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0032] Furthermore, reference numerals and / or reference letters may be repeated in different examples in this application. Such repetition is for simplification and clarity purposes and does not in itself indicate a relationship between the various embodiments and / or settings discussed. In addition, this application provides examples of various specific processes and materials; however, those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0033] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0034] Traditional COB technology typically uses a pure gold wire + holder IR solution, but it faces two major risks in automotive module applications. First, automotive modules have high reliability requirements, long operating times, and the gold wire is at risk of short circuits under vibration and mechanical shock. Second, the reflection from the gold wire may cause flare (in optics and photography, flare usually refers to stray light caused by unnecessary reflection and scattering of light inside or on the lens surface), affecting the display effect.

[0035] This utility model discloses a COB packaging structure that can solve the technical problem of unstable gold wires in the prior art, thereby effectively avoiding the risk of short circuit caused by vibration and mechanical impact during long-term operation of the module, and reducing the risk of module flare caused by gold wire reflection.

[0036] The technical solution of this application will be described in detail below through specific embodiments:

[0037] See Figure 1 , Figure 2 , Figure 3 , Figure 4 as well as Figure 5This application provides a COB packaging structure, which includes a circuit board assembly 100 (PCBA board), a fixing assembly 200, a sensor 300, gold wire adhesive 400, gold wire 500, and a first dam adhesive 600. The fixing assembly 200 covers the circuit board assembly 100 and together with the circuit board assembly 100 forms a mounting cavity 110. The sensor 300 is mounted on the circuit board assembly 100 and is located within the mounting cavity 110. The gold wire adhesive 400 surrounds the sidewall of the sensor 300 and is connected to the circuit board assembly 100. Both ends of the gold wire 500 are electrically connected to the sensor 300 and the circuit board assembly 100, respectively, and one end of the gold wire 500 connected to the circuit board assembly 100 passes through the gold wire adhesive 400. A gold wire 500 is provided on each sidewall of the sensor 300 where the gold wire adhesive 400 is provided. The first dam adhesive 600 is disposed on the top of the sensor 300, and one end of the gold wire 500 connected to the sensor 300 passes through the first dam adhesive 600.

[0038] PCBA is short for Printed Circuit Board Assembly, also known as PCB assembly or PCB board. It refers to a circuit board assembly with specific functions formed by assembling electronic components (such as resistors, capacitors, inductors, diodes, transistors, integrated circuits, etc.) onto a printed circuit board (PCB) through certain processes (such as through-hole insertion, surface mounting, soldering, etc.).

[0039] Gold wire adhesive 400 is typically made of high-molecular materials, characterized by high performance and high viscosity. It possesses excellent waterproof, moisture-proof, and shockproof properties, protecting internal components from environmental influences and extending product lifespan. Furthermore, gold wire adhesive 400 exhibits superior electrical properties, weather resistance, and strong adhesion, adhering tightly to the surface of gold wire 500 to form a robust protective layer, effectively preventing physical damage to the gold wire 500. Gold wire adhesive 400 is commonly used for encapsulating electronic components such as integrated circuits, transistors, and microchips. These electronic components require an effective encapsulation material to protect their internal circuits and components, while also considering factors such as thermal conductivity, insulation, and corrosion resistance. Due to its excellent physical and chemical properties, gold wire adhesive 400 is ideally suited for this purpose.

[0040] Damping adhesive, also known as chip damming adhesive or cofferdam filler adhesive, is a type of adhesive used for COB packaging and 500-inch chip integrated gold wire packaging. It is mainly divided into two types: one-component and two-component. Two-component damming adhesive requires the two components to be thoroughly mixed before use, while one-component damming adhesive can be used directly.

[0041] The COB packaging structure disclosed in this embodiment improves the reliability and stability of the packaging by adding gold wire adhesive 400, first damming adhesive 600, and fixing component 200, reducing the risk of gold wire 500 breaking or short-circuiting due to vibration. Simultaneously, the gold wire adhesive 400 and fixing component 200 provide additional protection for the sensor 300, shielding it from external environmental influences. Completely encapsulating the gold wire 500 with gold wire adhesive 400 and damming adhesive 600 effectively reduces the risk of module flare caused by reflection from the gold wire 500.

[0042] When filling with gold wire adhesive 400, it is typically applied directly along the height of sensor 300, ensuring the height of adhesive 400 exceeds that of sensor 300. When connecting circuit board assembly 100 to sensor 300, gold wire 500 is usually extended above sensor 300 before bending and connecting to the top of sensor 300. First damming adhesive 600 wraps around the bent portion of gold wire 500, ensuring complete coverage. After passing through gold wire adhesive 400 and first damming adhesive 600, the gold wire 500's two ends are electrically connected to sensor 300 and circuit board assembly 100, respectively.

[0043] In one embodiment, the first dam adhesive 600 is ring-shaped along the circumference of the sensor 300. The ring-shaped first dam adhesive 600 ensures that all the gold wires 500 are covered by the first dam adhesive 600, thereby ensuring that the gold wires 500 are completely wrapped by the gold wire adhesive 400 and the first dam adhesive 600, reducing the risk of module flare caused by the reflection of the gold wires 500.

[0044] See Figure 3 , Figure 4 and Figure 5 In one embodiment, the gold thread adhesive 400 is connected to the first dam adhesive 600, and the gold thread 500 is threaded through the gold thread adhesive 400 and the first dam adhesive 600. This ensures that the gold thread 500 is fully wrapped, thereby reducing the risk of breakage and reflection.

[0045] See Figure 4 In one embodiment, the height of the gold wire adhesive 400 is greater than the height of the sensor 300, and the portion of the gold wire adhesive 400 extending beyond the sensor 300 is connected to the first cofferdam adhesive 600. The gold wire adhesive 400, extending beyond the sensor 300 and connecting to the first cofferdam adhesive 600, forms a continuous wrapping layer around the gold wire 500, thereby preventing the gold wire 500 from reflecting light. This protective layer effectively isolates the sensor 300 from external environmental corrosion, improving the overall sealing and protection capabilities of the encapsulation structure.

[0046] The gold wire adhesive 400 not only serves as an electrical connection material but also provides additional support. Its height exceeds that of the sensor 300 and it connects with the first cofferdam adhesive 600, providing more stable support for the sensor 300 and enhancing the mechanical stability of the encapsulation structure.

[0047] In one embodiment, the top of the gold wire adhesive 400 is flush with the top of the first cofferdam adhesive 600. When the tops of the gold wire adhesive 400 and the first cofferdam adhesive 600 are flush, they can together form a continuous, flat, and tight sealing layer. In encapsulation scenarios requiring good hermeticity, such as certain environmentally sensitive sensor applications, the flush top structure helps to achieve better hermeticity. It can reduce gas exchange between the internal and external environments and maintain stable environmental conditions inside the encapsulation structure.

[0048] When the encapsulation structure is subjected to external pressure, vibration, or thermal stress, the flush top structure allows the gold wire adhesive 400 and the first dam adhesive 600 to bear these external forces more evenly.

[0049] See Figure 2 , Figure 3 and Figure 4 In one embodiment, the COB packaging structure further includes a second confining adhesive 700, which is located at the bottom of the gold wire bonding adhesive 400 and on the side of the gold wire bonding adhesive 400 opposite to the sensor 300. The second confining adhesive 700 is annular along the circumference of the sensor 300. The second confining adhesive 700 is used to further increase the reliability and stability of the packaging.

[0050] The second coping adhesive 700 is applied outside the gold wire bond 400, forming an additional sealing layer. This helps prevent moisture, dust, and other contaminants from entering the encapsulation structure, thus protecting the sensor 300 and the gold wire bond 400 from corrosion. Adding the second coping adhesive 700 further enhances the waterproof, dustproof, and corrosion-resistant capabilities of the encapsulation structure, ensuring the sensor 300 functions properly even in harsh environments. The addition of the second coping adhesive 700 also strengthens the overall mechanical properties of the encapsulation structure.

[0051] In one embodiment, the second dam adhesive 700 is spaced apart from the sensor 300.

[0052] If the second dam adhesive 700 comes into direct contact with the sensor 300, it may generate mechanical stress on the sensor 300 when the encapsulation structure is subjected to external force or thermal expansion and contraction, affecting the performance and accuracy of the sensor 300. The spacing setting can avoid this mechanical interference.

[0053] In one embodiment, the height of the second dam adhesive 700 is less than the height of the gold wire adhesive 400 to ensure that the gold wire adhesive 400 can fully fill the outside of the sensor 300.

[0054] The second encapsulating adhesive 700 serves as the initial sealing layer between the gold wire adhesive 400 and the fixing component 200. Its lower height allows the gold wire adhesive 400 to better fill and cover the gaps around the sensor 300 during the curing process. This ensures that the gold wire adhesive 400 can form a continuous, dense protective layer, thereby improving the overall sealing performance of the encapsulation structure.

[0055] In one embodiment, gold wire adhesive 400 is provided on three sidewalls of sensor 300, and correspondingly, gold wire 500 is provided on the corresponding three sidewalls of sensor 300.

[0056] During operation, the sensor 300 may face vibrations and stresses in different directions. Applying gold wire adhesive 400 to three sidewalls allows for the fixation of the gold wire 500 from multiple directions. Compared to applying gold wire adhesive 400 to only a few sidewalls, this method effectively reduces the amplitude of the gold wire 500's movement in various directions, lowering the risk of breakage or loosening due to frequent movement, thereby ensuring the stability and reliability of the electrical connection between the sensor 300 and the circuit board assembly 100.

[0057] Setting gold thread 500 on three side walls is sufficient to meet the requirements. However, setting gold thread adhesive 400 and gold thread 500 on all four side walls may increase the cost.

[0058] In one embodiment, the sensor 300 is bonded to the circuit board assembly 100. Of course, bonding is only one implementation method in this embodiment; in other embodiments, the sensor 300 and the circuit board assembly 100 may be electrically connected by soldering or other methods. This direct physical connection ensures stable and reliable signal transmission. Direct bonding reduces intermediate connection links, thereby reducing the risk of electromagnetic interference and signal loss, and improving the overall electrical performance of the system.

[0059] Through the above embodiments, this application has the following beneficial effects or advantages: The COB packaging structure disclosed in this application forms a stable mounting cavity 110 through the tight fit between the fixing component 200 and the circuit board assembly 100, providing a stable mounting environment for the sensor 300. This reduces the risk of performance degradation or damage to the sensor 300 due to unstable position during the packaging process. The filling of the gold wire adhesive 400 can effectively fix the gold wire 500, preventing the solder ends of the gold wire 500 from falling off the circuit board assembly 100. At the same time, the gold wire adhesive 400, which completely wraps the gold wire 500, can also reduce the risk of module flare caused by the reflection of the gold wire 500. The addition of the second dam adhesive 700 enhances the overall mechanical strength of the packaging structure. As a support layer between the gold wire adhesive 400 and the fixing component 200, it can resist external impacts and vibrations, reducing the risk of damage to the packaging structure due to external forces. The first dam adhesive 600 is used to cooperate with the gold wire adhesive 400 to ensure that the gold wire 500 can be completely wrapped.

[0060] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model have been clearly and completely described above with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0061] Therefore, the above detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0062] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0063] In the description of this utility model, it should be understood that the terms indicating orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0064] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0065] In this invention, unless otherwise expressly specified and limited, "above or below" the first feature may include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on" the first feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the first feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0066] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0067] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A COB packaging structure, characterized in that, include: Circuit board assembly; A fixing component is provided on the circuit board assembly and together with the circuit board assembly forms a mounting cavity; A sensor is mounted on the circuit board assembly, and the sensor is located within the mounting cavity; Gold wire adhesive is applied to the sidewall of the sensor and is connected to the circuit board assembly. A gold wire, with both ends electrically connected to the sensor and the circuit board assembly respectively, and the end of the gold wire connected to the circuit board assembly passing through the gold wire adhesive, wherein the gold wire is disposed on each sidewall of the sensor where the gold wire adhesive is disposed; and The first dam adhesive is disposed on the top of the sensor, and the end of the gold wire connected to the sensor passes through the first dam adhesive.

2. The COB packaging structure according to claim 1, characterized in that, The first dam adhesive is ring-shaped along the circumference of the sensor.

3. The COB package structure of claim 1, wherein, The gold thread adhesive is connected to the first dam adhesive, and the gold thread is threaded through the gold thread adhesive and the first dam adhesive.

4. The COB packaging structure according to claim 3, characterized in that, The height of the gold wire adhesive is greater than the height of the sensor, and the first dam adhesive is connected to the portion of the gold wire adhesive that extends beyond the sensor.

5. The COB package structure of claim 4, wherein, The top of the gold thread adhesive is flush with the top of the first dam adhesive.

6. The COB package structure of claim 1, wherein, It also includes a second dammed adhesive, which is located at the bottom of the gold wire adhesive and on the side of the gold wire adhesive away from the sensor. The second dammed adhesive is ring-shaped along the circumference of the sensor.

7. The COB package structure of claim 6, wherein, The second dam adhesive is spaced apart from the sensor.

8. The COB package structure of claim 6, wherein, The height of the second dam adhesive is less than the height of the gold thread adhesive.

9. The COB packaging structure according to any one of claims 1 to 8, characterized in that, The gold wire adhesive is applied to the three sidewalls of the sensor.

10. The COB packaging structure according to any one of claims 1 to 8, characterized in that, The sensor is attached to the circuit board assembly.

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