The printed circuit board is called "the mother of electronic system products", which directly determines the quality and competitiveness of electronic products. The copper clad laminate is the most important raw material in the printed circuit board. With the advent of the 5G era, traditional epoxy-based copper-clad laminates and polyimide-based copper-clad laminates have been unable to meet the transmission performance requirements of 5G high-frequency high-speed, ultra-large capacity, and ultra-low latency, thus giving high-frequency copper-clad laminate materials The development of has brought historic opportunities. LCP-based copper clad laminates are considered to be the best key supporting materials in the 5G commercial era due to their unique comprehensive performance advantages.
Challenge 1 Domestic companies used for the development of LCP resins for film production are generally small in scale and have weak technical strength. It is difficult to narrow the gap with their counterparts in the US in the short term;
Challenge 2 The material properties of LCP resin determine its film production equipment and process is very difficult, cut off the material supply base of domestic producers for large-scale production of LCP-FCCL, can only be purchased from the United States and Japan;
Challenge 3 LCP film production, post-processing and LCP-based copper clad laminate processing equipment basically rely on imports. Therefore, if the LCP film cannot be successfully broken through, it will seriously restrict the large-scale commercialization of 5G technology and become a "card" that restricts the development of China's 5G industrialization. "Neck" material technology;
Challenge 4 The compound equipment of LCP film and copper foil used to rely heavily on imports in the past. The key is that the process accuracy requirements of the composite heat roller at high temperature are difficult to meet.
1. Legion has broken through the LCP film integration technology, and can provide LCP film integration solutions and products that meet the 5G commercial requirements;
2. Independently developed LCP-based copper clad laminate production line
In the equipment configuration of the production line, the most critical core is the working accuracy of the composite heat press roller, including the temperature control accuracy and machining accuracy. The temperature control accuracy of the hot-pressed composite rollers independently produced by Shanghai Lianjing can achieve 450 ℃ ± 1 ℃, which is at an absolute leading level in China. In addition, the mechanical precision control of the hot-pressed composite roll is also extremely critical. The design of the hot-pressed composite roller should fully consider the interactive effect of heating deformation and pressure deformation. In order to counteract the impact of thermal deformation, it is necessary to design a reasonable physical structure, correct material selection, and reasonable material heat treatment, and then supplement it with a specially developed processing technology to produce a counter-pressure composite roller that meets the composite requirements.
Combined with the characteristics of the LCP film material and the composite process, the required pressure is calculated according to the set rolling temperature, and then the deformation of the roller at this temperature and pressure is calculated, and then the corresponding middle and high height of the heating roller is designed according to this deformation. The roller is made into a "spindle" with a higher central area than the ends. In this way, the middle height of the roller can compensate for the thermal deformation after being pressed, and ensure that the thickness of the LCP copper clad laminate material obtained after rolling is uniform.
LCP film is a thermoplastic resin, which can be directly hot-pressed with copper foil at high temperature without pre-coating on the surface of the film. Therefore, the compounding process of PI film and copper foil is more concise, environmentally friendly and efficient than PI film.
In order to prevent the copper foil from oxidizing on the surface under high temperature compounding, it must be protected. Usually, a protective film is added as shown in the process flow chart, or a sealed nitrogen filling protection method in the compound process section can also be used.
Main process parameters of production line
Production line speed: 2 ~ 10m / min
Copper foil thickness: 8 ~ 35μm
LCP film thickness: 20 ~ 120μm
PI protective film thickness: 20 ~ 80μm
Hot pressing compound roller pressure range: 20 ~ 200kN
LCP-FCCL thickness: 40 ~ 160μm, thickness deviation: ± 1 ~ 2%