5G PCB faces new challenges

With the emergence of 5G scenarios, the PCB industry is facing new challenges, mainly in the following aspects:
1. Requirements for materials
A very clear direction for 5G PCB is high-frequency and high-speed materials and board manufacturing. In terms of high-frequency materials, the leading material manufacturers in the traditional high-speed field have begun to deploy high-frequency plates and introduced a series of new materials. This will break the current Rogers dominance in the field of high-frequency panels. After healthy competition, the performance, convenience and availability of materials will be greatly enhanced. The localization of high-frequency materials is an inevitable trend.
In terms of high-speed materials, the industry believes that 400G products need to use M7N, MW4000 equivalent grade materials. In the backplane design, M7N is already the lowest loss option. In the future, backplanes/optical modules with larger capacity will require lower loss materials. The combination of resin, copper foil, and glass cloth will achieve the best balance between electrical performance and cost. In addition, the number of high-levels and high density will also bring reliability challenges.
2. Requirements for PCB design
Relevant people in the industry believe that 5G’s requirements for PCB design are mainly manifested in that the selection of plates must meet the requirements of high frequency and high speed, impedance matching, stacking planning, wiring spacing/holes, etc. must meet the signal integrity requirements. You can start from the six aspects of loss, embedding, high-frequency phase/amplitude, mixing, heat dissipation, and PIM.

3. Requirements for process technology
The enhancement of 5G-related application product functions will increase the demand for high-density PCBs, and HDI PCB will also become an important technical field. Multi-level HDI products and even products with any level of interconnection will be popularized, and new technologies such as buried resistance and buried capacitance will also have more and more applications.
In addition, PCB copper thickness uniformity, line width accuracy, inter layer alignment, inter layer dielectric thickness, control accuracy of back drilling depth, and plasma de-drilling ability are all worthy of in-depth study.

4. Requirements for equipment and instruments
High-precision equipment and pre-processing lines with less roughening of the copper surface are currently ideal processing equipment; and testing equipment includes passive intermodulation testers, flying probe impedance testers, loss test equipment, etc.
The industry believes that sophisticated graphics transfer and vacuum etching equipment can monitor and feedback data changes in real-time line width and coupling distance detection equipment; electroplating equipment with good uniformity, high-precision lamination equipment, etc. can also meet 5G PCB Production needs.
5. Requirements for quality control

Due to the increase of 5G signal rate, the board-making deviation has a greater impact on the signal performance, which requires stricter control of the board-making production deviation, and the current mainstream board-making process and equipment are not updated, which will become the bottleneck of future technology development. It is very important for PCB manufacturers to break through this point.