Copper clad laminate (CCL) is the base material of printed circuit board (PCB). It has a great influence on the transmission speed, energy loss and characteristic impedance of the signal in the circuit. Therefore, the performance of PCB depends on the performance of CCL to a large extent.
1、 5g demand for high frequency copper clad laminates
PCB made of high-frequency copper clad laminate is at the top of the industry pyramid, with very low dielectric loss, which is suitable for 5g industry.
5g requires about 3 times as much PCB space as 4G; The demand for high frequency copper clad laminates is 4 ~ 8 times. The price of high-frequency and high-speed base materials is still significantly higher than that of ordinary base materials, about 10-40 times. In the next three years, the demand for high-frequency copper clad laminates will increase by 15 times. It is estimated that by 2025, the domestic demand for 5g base station antenna high-frequency substrate will be 33.8 billion. The cumulative global demand for vehicle mounted millimeter wave radar and Internet of things applications will reach 61.1 billion.
2、 Base material of high frequency copper clad laminate
At present, the common special resin materials for high-frequency and high-speed copper clad laminates mainly include hydrocarbon resin, PTFE, PPE (also known as PPO), LCP, maleimide resin, active ester, epoxy resin, etc. This article only enumerates some engineering plastic substrates.
PTFE, commonly known as the king of plastics, has low loss, small dielectric constant and good insulation. PTFE film is an ideal material for manufacturing capacitors, radio insulation pads, insulated cables, motors and transformers, and is also an indispensable material for industrial electronic components such as aerospace, military industry and 5g communication; The excellent dielectric properties of PTFE make it the main material of 5g high frequency copper clad laminate substrate.
It is estimated that the total market of PTFE for 5g base stations in China will reach 7.6 billion yuan from 2020 to 2025. According to the construction progress of 5g base stations of the three major operators, the launch peak will come in 2022. Superimposed on the demand of 5g mobile phones for PTFE, it is estimated that the 5g industry will generate about 1.7 billion yuan of new demand for PTFE in 2022.
2. PPE（PPO）
Polyphenylene oxide (PPE) has the advantages of low specific gravity, low water absorption, excellent heat and chemical resistance, good electrical insulation and excellent dielectric properties. At the same time, it also has the adhesion to copper foil, which is very suitable for high-frequency and high-speed copper clad laminates.
Bluestar new generation polyphenylene oxide has a controllable molecular weight design on the basis of maintaining electrochemical performance, which greatly improves the poor processing performance of traditional polyphenylene oxide.
3. LCP
As a liquid crystalline polymer, LCP has high strength, high heat resistance, very small coefficient of linear expansion, excellent flame retardancy, excellent dielectric properties and so on.
There are a large number of rigid benzene rings on the main chain of LCP molecules, which determines the unique processing properties of LCP. When LCP is heated to a certain temperature, it will have the same fluidity as water as long as a little shear force is given. This feature makes LCP easier to form thin-walled or thin-film products.
Electronics and electricity are the main market of LCP. In addition to flexible copper clad laminates, LCP can also be applied to mobile phone antennas, satellite electronic components, jet engine parts, automotive machinery parts, medical materials, etc.
3、 Status quo of high frequency copper clad laminate industry
The preparation process of high-frequency copper clad laminate is similar to that of ordinary copper clad laminate. Raw materials, process formula and process control are three important factors that affect the dielectric loss and dielectric constant of copper clad laminate. These three factors require a long time of experimental experience accumulation and downstream application product verification, building a core barrier for high-frequency copper clad laminate manufacturers with high technical threshold.