Printed Circuit Design & Fab - October 2008 - (Page 27)

Figure 3: Simple Directory Storage Library System. DESIGN toolS FiGurE 3. Simple directory storage library system. Figure 3: Simple Directory Storage Library System. FiGurE Parts Database Librarylibrary system. 4. Parts database System. Figure 4: larger company. For instance, if a division or company is spending 31% of its design time building missing geometries and symbols, and it generally completes 20 projects per year, the same company could be completing 26 projects per year. Along with faster time-to-market, this small increase in projects can increase annual revenue by millions of dollars (FiGurE 2). While designers and managers generally agree that a centralized library would help streamline the design flow, this suggestion is often met with a loud groan at the thought of having to set aside time and resources to create the library. These statistics should serve as an adequate motivation to illustrate that it’s time to get moving. The initial headaches of time and resource investment are far outweighed by the positiveParts Database Library System. lives for designers and Figure 4: gains in both daily work revenue stream for the entire company. Choosing a Library Format: Database or No Database? Library structures come in all flavors, and finding the best configuration for a company depends on many factors. But before examining these factors, it is important to remind ourselves of the simplicity of the concept: a library is a centralized location where information is available to users for the purpose of unifying and simplifying the design process. The library itself doesn’t have to be a complex web of information if the company environment doesn’t call for that. In the simplest version, a flat file directory structure can be more than enough for a smaller design group. This library would be a simple file and directory organization with the library name at the top of the directory structure, with symbols and geometries underneath and subfolders of appropriate OCTOBER 2008 categorizations beneath the symbol and geometry folders (FiGurE 3). When libraries are especially small, users can even read the entire library into each new schematic and layout and use whatever is needed, but in the more typical scenario, users would only bring in whatever symbols and geometries are needed for that specific design. At the minimum, even small companies are going to have libraries that are sizable enough to require an organized directory structure. How the directories and subdirectories are organized should be carefully decided based on the frequency that groups of symbols and geometries are used. For example, separating through-hole and surface mount geometries from one another usually helps layout designers locate exactly what they need quickly. This library structure should be considered adequate in smaller environments where the parts’ information tends to remain relatively static. For environments where parts information is constantly updated or changed according to availability and cost, there are many options for structures that utilize a parts database system to make it easier to maintain more rapidly changing information. A parts database system is useful for medium to large design teams, both for its faster performance for printEd CirCuit dESign & fAB 27 http://www.pcb-pool.com/ppus/info.html?PHPSESSID=7df48fa7c977776045ff8d4b24a70fc7 http://www.pcb-pool.com/ppus/info.html?PHPSESSID=7df48fa7c977776045ff8d4b24a70fc7

Table of Contents Feed for the Digital Edition of Printed Circuit Design & Fab - October 2008

Printed Circuit Design & Fab - October 2008 Contents Our Line Market Watch Around the World Happenings Test and Inspection ROI Tip Jar Interconnect Strategies Final Finish Forum The New Wave in High-Speed Modeling The PCB Design Library Mixed Signal Design Considerations Modeling Conductor Surface Roughness Copper Erosion: The Influence of Metallurgy on Copper Dissolution The Wave of the Future Ad Index Building a Profitable Niche Marketplace Off the Shelf BGA Bulletin

Printed Circuit Design & Fab - October 2008

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