In today's electronic manufacturing industry, environmental protection, safety, and high performance have become irreversible trends. Halogen free double-sided adhesive substrate, as a key material derived from traditional FR-4 substrate, perfectly meets these needs and plays an indispensable role in many electronic fields.
1、 What is halogen-free double-sided adhesive substrate?
To understand its purpose, it is necessary to first understand its composition:
Halogen free: refers to the low content of halogen elements such as bromine and chlorine in the reinforcing material (usually glass fiber cloth) and resin system (usually epoxy resin) of the substrate (usually meeting the requirements of IEC 61249-2-21 standard). Halogens produce toxic and corrosive dioxins and hydrogen halides during combustion, while halogen-free is for the protection of the environment and human health.
Adhesive: The term 'adhesive' here specifically refers to semi cured films. When manufacturing multi-layer printed circuit boards, the semi cured sheet is a B-stage resin material between the core boards, which melts, flows, and solidifies under high temperature and high pressure, firmly bonding the various layers of circuit core boards together and serving as interlayer insulation.
Double sided substrate: refers to a core board with double-sided copper coating, which can be etched on both sides to form the basis of the circuit.
Therefore, halogen-free double-sided adhesive substrate is essentially an environmentally friendly FR-4 copper-clad laminate, and its production system (including core board and semi cured sheet) is halogen-free formula, specifically used for manufacturing multi-layer printed circuit boards that require high reliability, high safety standards, and complex laminated structures.
2、 Core Features and Advantages
Environmental protection and safety: significant advantages. In the event of unexpected situations such as fires, it can significantly reduce the emission of toxic and corrosive gases, protect personnel and equipment safety, and comply with international environmental directives such as RoHS and REACH.
Excellent lamination bonding: Its halogen-free semi cured sheet has good flowability and filling ability, ensuring that there are no voids between layers and strong bonding force after lamination, ensuring the long-term reliability of the product.
Good electrical performance: With stable dielectric constant and dielectric loss factor, it can meet the requirements of most high-frequency digital circuits and high-speed signal transmission.
Reliable heat resistance: Halogen free flame retardant systems are usually achieved through compounds such as nitrogen and phosphorus, which have high glass transition temperature and thermal decomposition temperature, excellent heat resistance, and can withstand high temperature processes of lead-free soldering.
High mechanical strength: Maintaining the good mechanical properties of traditional FR-4 material, it is easy to drill holes, mill edges and other processing.
3、 Main uses and application areas
With the above advantages, halogen-free double-sided adhesive substrates have become a preferred material for the following electronic products:
1. Communication and network equipment
Smartphones/tablets: Modern mobile devices pursue lightweight, compact, and powerful functionality, with internal motherboards mostly consisting of high-density interconnected multi-layer boards. Halogen free materials are the foundation for meeting their environmental requirements and ensuring the reliability of complex structures.
Base stations and routers: These devices require 7x24 hours of uninterrupted operation and have high requirements for the long-term stability and heat resistance of PCBs. The halogen-free adhesive substrate can ensure stable operation of equipment in high temperature environments and meet the safety standards of the computer room.
Server/Data Center: As the core of the digital world, server motherboards have multiple layers, dense wiring, and high heat dissipation requirements. The environmental friendliness and high reliability of halogen-free materials are crucial here.
2. Automotive Electronics
Modern cars are gradually becoming 'computers on wheels'. The requirements for safety and reliability in automotive electronics are at a high level.
Engine control unit: located inside the high-temperature engine compartment, requiring the substrate to have high heat resistance and stability.
Advanced driving assistance systems: control boards for sensors such as radar and cameras, whose reliability directly affects driving safety.
Car infotainment system: The functions are complex, and the motherboard is mostly a multi-layer HDI board.
New energy vehicles: Core components such as battery management systems and motor controllers must use halogen-free and other high reliability materials to cope with high voltage, high current, and harsh working environments.
3. Consumer electronics products
In addition to mobile phones, it also includes:
Laptops and wearable devices: There are clear requirements for slimness and environmental friendliness.
TV and game console: powerful performance, complex motherboard design, requiring high-quality multi-layer board support.
4. Industrial control and medical equipment
Industrial computers PLC、 Inverter: In harsh industrial environments with strong electromagnetic interference and large temperature differences, PCB materials are required to have excellent stability and environmental resistance.
Medical equipment: such as monitors, endoscopes, ultrasound devices, etc. These devices are directly related to human life and have very strict requirements for the long-term reliability and non toxicity of PCBs. Halogen free materials are an inevitable choice.
5. Aerospace and Military Industries
Although there are more specialized material systems, high reliability halogen-free adhesive substrates are also being applied in some non core electronic systems to meet their increasing demands for safety and environmental protection.
4、 Summary
Halogen free double-sided adhesive substrate is not a basic material, but an advanced choice designed to meet the requirements of high-performance, high reliability, and high safety electronic products. It represents the direction of PCB material technology towards environmental protection and development. From the smartphones in our hands, to the cars that ensure our safety, to the servers that support the digital society, the precise "brain" inside - multi-layer printed circuit boards - all rely on this environmentally friendly and reliable cornerstone material. With the continuous advancement of technology, its application fields will continue to expand.
