Impact of flexible PCB on DDR4 channel memor performance

Infotainment and PCB miniaturization are one of the challenges of many companies. Reduce the overall dimension of the devices preserving the high efficiency in terms of data transfer rate and power consumption is one of the missions in this century. However one of the limits of miniaturization was the memory dimension and memory placement on PCB. In many cases more than 30% of the PCB area was dedicated to the memory chip, and this can have an impact on miniaturization. In this paper we will evaluate a new technique that can reduce the impact of LPDDDR using a flexible connection between the main PCB and the PCB where all the memories are placed. We are calling, this technique, “Flex-DIMM”. It offers numerous advantages over the traditional memory-down approach, for example the same behavior reducing the PCB area. Another advantage of this technique was provided a plug-n-play approach for memory channels, this dramatically reduce the design cycle of embedded systems and the routing of the memory channel can be omitted. While the advantages in term of space reduction and placement optimization had, the impact on the high-speed memory channel, signal integrity, power integrity and EMC need to investigate dipper. The aim of this paper was to investigate a DDR4-2667, placed on new Rigid-Flex-PCB architecture, and evaluate the effect, of different flexible PCB configurations, on the main figure of merit in EMC term such as eye-opening and radiated emission and compare the performance to the traditional memory-down approach The investigation was done using a full wave 3D electromagnetic analysis performed by CST Studio suite 2016. We will also study the effect of bending angle and radius.