第十四章 PCB规则约束及校验.pdf

Specifying the PCB Design Rules and Resolving Violations Summary This article introduces the PCB Design Rules System, in particular how rules are created and applied to objects in a design. It also describes how defined rules are Article checked using online or batch DRC tools and discusses navigating and resolving violations. AR0111 (v1.2) March 3, 2008 PCB design is no longer a matter of simply placing tracks to create connections. In fact, many complex designs can be a minefield of conflicting requirements. High speed logic combined with smaller and more complex packaging technologies place extreme demands on the PCB Designer. It is not possible to satisfy all the requirements of the design by only considering the clearance between tracks, pads and vias. Designs today can also require that you apply specific requirements to individual nets, components or regions of the board as well as considering such issues as net impedance, crosstalk, signal reflections and path lengths. Altium Designers rules-driven PCB Editor allows you to define design rules that monitor and test for these and other requirements. Design rules collectively form an instruction set for the PCB Editor to follow. Each rule represents a requirement of your design and many of the rules, for example clearance and width constraints, can be monitored as you work by the Online Design Rule Checker (DRC). Certain rules are monitored when using additional features of the software, for example routing-based rules when routing a design – either interactively or using the Situs Autorouter – or signal integrity-based rules used by the Signal Integrity Analyzer when performing a detailed signal integrity analysis of a design. Armed with a w