Issue link: https://iconnect007.uberflip.com/i/994883
24 DESIGN007 MAGAZINE I JUNE 2018 evaluating whether a two-board or three-board design is best, and which blocks should be allocated to which board. 3D Design Challenges To compensate for increasing silicon costs, new packaging technologies have emerged to pack ICs more closely together. PoP structures are being used to connect logic and RAM ICs. SiP integration is being used to integrate mul- tiple chips into a single package. And 3D-IC technology using through-silicon vias (TSV) is being used to reduce interconnect distance in stacked chip configurations. Meanwhile, PCB technology has evolved over the years with high density interconnect PCBs, high den- sity packaging, embedded components and advanced I/O technology. The greater complexity of these new packag- ing configurations is creating major challenges for packaging designers as well as for the PCB and IC designers who must integrate the pack- age into their own work. Traditionally, the PCB, the IC and the package are each designed in their own stand-alone 2D environment. PCB design software has been enhanced to address technology advancements with improvements in routing, constraint management, and sig- nal and power integrity analysis. But these improvements have largely been limited in scope to the PCB design process. With increasing functionality, tighter cost constraints, and the decreasing form factor of today's products, such as portables, wearables and the Internet of Things (IoT), components need to be tightly coordinated with each other so that pin assignments can be optimized for small size and minimum layer count sub- strates. The overall goal is to align the board, package and chip so that each signal follows the shortest possible path from the chip to the board, resulting in the fewest possible layers in the package. With the lack of tool integration, but increasing design requirements, engineers have reverted to workarounds such as using spreadsheets and generic office productivity tools to perform planning and feasibility stud- ies, and to define the tool interfaces and data transfer. 3D Design Tools Address Multi-board Design A new generation of 3D multi-board, chip- package-board co-design tools addresses these challenges by providing an environment for system design that integrates 2D and 3D multi- board design along with the chip and package. Designers can manage all of the boards in the system in a single view to define the connec - tions between them and then highlight the signal across each entity and analyze the entire inter - connect length. The number, size, type and configuration Figure 3: A product-level multi-board schematic.