Issue link: https://iconnect007.uberflip.com/i/275965
16 The PCB Design Magazine • March 2014 autorouters, and others have matured, dramati- cally reducing time to market. But, even though most EDA tool providers have enhanced their tools through integration of new functionality or acquisition, some areas of inherent ineffi- ciency in PCB CAD tools remain. Post-Design Documentation: Late to the Party? One glaring example of this: The documen- tation required for fabrication and assembly of the PCB. Comprehensive PCB doc- umentation is a requirement today, and if the end-product is destined for a military or aerospace user, the documen- tation requirements ratchet up considerably. Yet the majority of PCB documentation is created using PCB CAD drafting fea- tures that have not improved since the CAD revolution of the 1980s. CAD tools are superlative at reducing the PCB design cycle, but they fall short on some of the most basic documentation tasks. For example, PCB de- sign tools that sell for tens of thousands of dollars per seat lack the spell-checking found in $99 word proces- sor software. Most CAD tools lack support for a paragraph requiring the user to create multiline text strings as basic fabrication notes. Countless hours are spent using rudi- mentary drafting tools to cre- ate PCB detail views and drill charts, one segment or one line at a time. These antiquated methods show their real colors during a design re-spin. Drill quantities out of sync in a manually drawn drill chart? Select the text string and edit the value. PCB detail view need updating because a com- ponent moved on the PCB? Either recapture the entire view or start editing the graphics one ver- tex or one segment at a time. Some engineer- ing organizations have resolved to use popular MCAD tools to complete the PCB documenta- tion. MCAD tools are superior to PCB CAD tools with respect to creating documentation. However, converting the design to MCAD file formats results in disassembling the intel- ligent PCB CAD data. Parts are converted to shapes, traces to lines, copper shapes to poly- gons, and so on. Creating tables, notes, com- plex dimensions is certainly quicker, but culti- vating intelligent data for a parts list is no longer possible with MCAD tools. Should a design re-spin be required, the MCAD drawings must often be rec- reated or manually updated with new design content. It also introduces an MCAD de- sign database to an already crowded PCB documentation file collection. Maintaining synchronicity between PCB and MCAD design databases becomes the responsibility of the user. The bottom line: Creat- ing PCB documentation is not free or well automated in PCB CAD tools. Every PCB design has its share of tasks related to documentation. Some docu- mentation sets can be dozens of drawing sheets. Stringent documentation standards for military, aerospace, automo- tive and other segments re- quire highly detailed, time- consuming documentation sets. Documentation require- ments are not limited to one department across an entire organization. Many downstream processes in product manufacturing have unique documentation requirements. This includes PCB rework instructions, assembly pro- cess steps, PCB panel fabrication drawing, as- sembly inspection, and more. There is more to a PCB documentation set than a simple one-sheet assembly and fabrication drawing. All of these feature MITIGATING THE HIGH COST OF PCB DOCuMENTATION continues Every PCB design has its share of tasks related to documentation. Stringent documentation standards for military, aerospace, automotive and other segments require highly detailed, time-consuming documen- tation sets. Documentation requirements are not limited to one department across an entire organiza- tion. Many downstream processes in product manufacturing have unique documentation requirements. " "