The core difference between Flip-chip COB and Formal COB technology lies in the installation method: Formal COB directly sticks the front of the chip on the PCB, which is suitable for conventional optical design and thermal management; while Flip-chip COB flips the chip for installation, and by changing the lighting direction and optimizing the heat dissipation performance, it provides more flexible optical design and higher heat dissipation efficiency, which is suitable for application scenarios that require special effects and high performance.
Introduction
In the field of LED display screens, COB (Chip-On-Board) packaging technology is an important technical form, and Flip-chip COB and Formal COB are two different implementation methods.
Although the ultimate goal of both is to achieve a close combination of LED chips and substrates, there are significant differences in technical implementation, performance and application scenarios.
This article will explore the difference between Flip-chip COB and Formal COB technology in depth, in order to provide a comprehensive understanding and reference for relevant practitioners and consumers.
Technical principle and implementation
Formal COB technology
Formal COB technology, also known as traditional COB technology, is to directly paste the LED chip on the PCB (printed circuit board) substrate with the front side facing up, and connect the chip and the substrate through wires.
The key to this technology is to achieve a close combination between the chip and the PCB to provide good heat dissipation performance and electrical connection.
Formal COB technology is suitable for scenes with large chip size and small number such as light-emitting diodes, and can achieve high-resolution and high-brightness display effects.
The specific implementation steps include: applying a layer of thermal conductive glue on the PCB substrate, and then placing the LED chip on the thermal conductive glue with the front side facing up, and tightly combining the chip and the substrate through heating and pressure.
Then, connect the chip and the substrate through wires to achieve electrical connection. Finally, the entire package is tested and quality controlled to ensure the stability and reliability of the product.
Flip COB technology
Flip COB technology is a special technology for flipping the COB light source component. In this technology, the electrode side of the LED chip is connected to the substrate with the electrode side facing down, instead of facing up like the formal COB.
The key to this technology is to change the lighting direction and installation method of the light source to provide more flexible optical design and heat dissipation performance.
The specific implementation steps include: pre-setting some metal bumps or solder joints on the PCB substrate as connection points, and then turning the LED chip over so that its electrode surface is facing down to align and connect with these connection points.
After the connection is completed, an electrical connection is established between the chip and the substrate through wire bonding or other methods. Finally, the entire package is tested and quality controlled to ensure the stability and reliability of the product.
Performance
Optical control
The upright COB technology is usually suitable for conventional optical design, such as light control and focusing through lenses or reflectors. The flip-chip COB technology can change the lighting direction of the light source, provide more flexible optical design, and adapt to different lighting needs. For example, in situations where special angle lighting or uniform lighting is required, the flip-chip COB technology can achieve more precise optical control.
Heat dissipation performance
The upright COB technology uses thermal conductive glue to tightly combine the chip and the substrate to achieve better heat dissipation performance. The flip-chip COB technology can further optimize the heat dissipation performance by changing the installation direction of the light source.
Since the electrode is connected to the substrate with the face down, the heat can be conducted more directly to the substrate, improving the heat dissipation efficiency. This is especially important for high-brightness, high-density LED displays, which can effectively reduce the operating temperature of the LED chip and extend its service life.
Design flexibility
The front-mounted COB technology is relatively limited in design because the front-mounted installation of the chip limits the lighting direction and installation position of the light source. The flip-chip COB technology provides more design flexibility and freedom. Designers can choose the appropriate installation angle and position according to specific application requirements to meet different lighting effects and installation requirements.
Thermal management
The thermal management of the front-mounted COB technology mainly depends on the design of the heat dissipation substrate or lamp. In some occasions where efficient heat dissipation is required, additional heat dissipation structures may be required to maintain a suitable operating temperature. The flip-chip COB technology can better match the design requirements of specific lamps or heat dissipation systems by changing the installation direction of the light source and optimizing the heat dissipation structure, thereby improving the overall thermal management effect.
Application scenarios
Formal COB technology
Formal COB technology is suitable for scenes with high image quality requirements and large chip size and small number.
For example, in some high-end conference rooms, command centers and other occasions, the upright COB technology can achieve high-resolution and high-brightness display effects, meeting the user’s requirements for picture quality and stability.
Flip-chip COB technology
Flip-chip COB technology is more suitable for occasions that require special optical design and efficient heat dissipation.
For example, in outdoor billboards, stage lighting, automotive lighting and other applications, flip-chip COB technology can achieve more flexible optical design and higher heat dissipation efficiency, meeting special lighting requirements and long-term stable operation requirements.
Summary
There are significant differences between flip-chip COB and upright COB technology in technical principles, performance and application scenarios.
The upright COB technology is suitable for conventional optical design and heat dissipation requirements, while the flip-chip COB technology provides more flexible optical design and heat dissipation performance optimization.
In practical applications, it is necessary to select appropriate technical solutions according to specific needs and scenarios.
At the same time, with the continuous development of LED display technology and the continuous expansion of application needs, it is believed that both flip-chip COB and upright COB technologies will continue to play an important role and bring more convenience and fun to people’s lives and work.