Anisotropic Conductive Film (ACF), also known as ACF Tape, is a special adhesive material used to create electrical and mechanical connections between two substrates.
It was first developed by Sony Chemical in 1973.
ACF consists
ACF consists of conductive particles (usually metal particles such as gold, silver, or copper, or polymer particles coated with metal) dispersed in an insulating adhesive matrix, which is typically made of thermoplastic or thermosetting resins such as epoxy resin, acrylic resin, or polyurethane.
The conductive particles are evenly distributed in the film, and their size, shape, and distribution density play a crucial role in determining the electrical conductivity of the ACF.
Working Principle
The unique feature of ACF is its anisotropic conductivity, meaning it conducts electricity in the vertical direction (Z-axis) .but remains insulating in the horizontal directions (X and Y axes).
During the bonding process, the ACF is placed between two substrates, and heat and pressure are applied.
The conductive particles are compressed and form contact points between the electrodes of the substrates, creating conductive paths.
The uncompressed conductive particles remain dispersed in the resin, ensuring that adjacent electrodes do not short-circuit.
This results in a stable structure that achieves vertical electrical conduction and horizontal insulation.
Applications
ACF is widely used in the electronics industry, particularly in the assembly of displays and automotive systems.
It is used in various configurations such as COG (Chip on Glass), COF (Chip on Film), FOG (Flex on Glass), and FOB (Flex on Board).
In smartphones, tablets, computers, and televisions, ACF is used for electrical connections and physical fixation between LCD/OLED substrates, ICs, flexible circuit boards, and circuit boards.
In the automotive industry, ACF is used in advanced driver assistance systems (ADAS) to connect cameras and other sensors to PCBs, providing a more reliable and cost-effective solution compared to traditional connectors.
Advantages
Cost Savings: ACF interconnects offer a lower-cost alternative to traditional mechanical connectors and soldering methods.
Fine Pitch Capability: ACF bonding can handle very fine pitches, enabling higher density and miniaturization of assemblies.
Reliability: The use of environmentally friendly materials and advanced manufacturing processes ensures high reliability and durability of the connections.
Automation: ACF bonding can be easily integrated into automated assembly processes, improving production efficiency.
Market Trends and Future Prospects
The ACF market is expected to grow significantly in the coming years due to the increasing demand for high-performance and multifunctional materials in various industries.
The rise of autonomous driving systems and the increasing use of displays and cameras in vehicles will further drive the demand for ACF.
Additionally, the development of highly reliable ACF for ultra-fine pitch bonding processes will expand its applications in the electronics and automotive industries.
In conclusion, ACF is a versatile and reliable material that plays a crucial role in modern electronics and automotive assemblies.
Its unique properties and cost-effectiveness make it a preferred choice for fine pitch connections and other advanced applications.
ACF bonding
ACF bonding is a process used to create electrical and mechanical connections between various substrates, such as flexible and rigid circuit boards, glass panel displays, and flex foils. It is particularly useful for applications with very fine pitch (<30 μm) connections.
Working Principle
ACF bonding utilizes Anisotropic Conductive Film (ACF), which contains conductive particles dispersed in an adhesive matrix. The conductive particles are typically made of metals such as gold, silver, or copper, or polymer particles coated with metal.
When heat and pressure are applied, the conductive particles form conductive paths between the electrodes of the substrates, while the uncompressed particles remain dispersed in the resin, ensuring insulation in the horizontal directions.
Applications
ACF bonding is widely used in various industries, including:
LCD and LED Panel Manufacturing: For bonding ICs, FPCs, and other components to glass substrates.
Flexible Circuit Assembly: For creating connections between flexible printed circuits and other components.
Touch Screen Production: For bonding touch sensors to display panels.
Mobile Phone and Tablet Manufacturing: For assembling components in mobile devices.
Types of ACF Bonding Machines
ACF Pre-Bonding Machines: Used for the initial alignment and attachment of ACF tape to the substrates.
ACF Main-Bonding Machines: Responsible for the final bonding process under precise temperature and pressure conditions.
ACF Heat Press Machines: Versatile tools used for bonding components using ACF, with features like multi-stage temperature control and CCD vision systems.
Pulse Heating Bonding Machines: Use a transformer to generate low voltage and high current for rapid heating and cooling, ideal for quick and precise bonding.
Constant Temperature Bonding Machines: Maintain a steady temperature throughout the bonding process, widely used in LCD panel assembly.
Industry Trends and Future Prospects
The ACF bonding market is expected to grow significantly due to the increasing demand for high-performance and multifunctional materials in various industries.
The rise of autonomous driving systems and the increasing use of displays and cameras in vehicles will further drive the demand for ACF bonding.
Additionally, the development of highly reliable ACF for ultra-fine pitch bonding processes will expand its applications in the electronics and automotive industries.
In conclusion, ACF bonding is a versatile and reliable technology that plays a crucial role in modern electronics and automotive assemblies.
Its unique properties and cost-effectiveness make it a preferred choice for fine pitch connections and other advanced applications.
Applications of ACF Bonding
Electronics Industry: ACF bonding is widely used in the electronics industry for applications such as LCD, OLED, and other display technologies.
It is used in various configurations including COG (Chip on Glass), COF (Chip on Film), FOG (Flex on Glass), and FOB (Flex on Board).
Automotive Industry: ACF bonding is becoming a key technology in the automotive industry, particularly for advanced driver assistance systems (ADAS).
It is used to connect cameras and other sensors to PCBs, providing a more reliable and cost-effective solution compared to traditional connectors.
Display and Camera Applications: ACF bonding is ideal for fine-pitch applications, enabling smaller and more efficient connections. It supports pitches as small as 30 microns, making it suitable for high-resolution cameras and displays.
Advantages of ACF Bonding
Cost Savings: ACF interconnects offer a lower-cost alternative to traditional mechanical connectors and soldering methods.
Fine Pitch Capability: ACF bonding can handle very fine pitches, enabling higher density and miniaturization of assemblies.
Reliability: The use of environmentally friendly materials and advanced manufacturing processes ensures high reliability and durability of the connections.
Automation: ACF bonding can be easily integrated into automated assembly processes, improving production efficiency
