Preparing for the 'Left Shift' in Design for Fabrication Analysis

摘要

The need for Design for Manufacturing (DfM) and, more specifically, Design for Fabrication (DfF) checks as a part of the overall PCB design process are well documented. Articles in many of the industry trade magazines over the past few years have detailed both the wide range of DfF rules, which should be analyzed, along with the benefits of doing so. All PCB fabricators use sophisticated (and not-so-sophisticated) tools to prepare the data from their CAD system prior to ramping up their manufacturing lines. So what is the problem? You send the data, they fix it and you get a board prototype back that functions as expected first time, right? But what does it mean to "prepare the data from your CAD system"? Think about that for a minute. The PCB designer works diligently with the engineer to ensure that all of the signal integrity requirements are met and then the fabricator manipulates the data to adjust for specific processes and tolerances. But that works because you used an appropriate set of design rules that allowed for different process tolerances-and you always use the same fabricator. Good!