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Collaboration Takes the Sting Out of PCB Design

In August 2008, IPC made the assertion that 75 percent of the impact on the manufacturability and profitability of a printed circuit board (PCB) design occurred in the design phase, and only 25 percent of the potential impact to make a design profitable took place once it was complete. Given the importance of decisions made during design, it only makes sense to take a closer look at the design process and examine where and how methodology can be improved and optimized to reduce a project's turn time and enhance a company's bottom line.

Bucking Tradition
Traditionally, the design process for PCBs has been fairly segregated, with different suppliers and stakeholders taking ownership for just a portion of the design process. For instance, IC manufacturers will assist in the identification, selection and physical packaging for parts by providing technical and sales information. Parts distributors will help with final parts selection and delivery, while the PCB CAD vendor focuses on creating schematic symbols and a PCB footprint for a part. As a result of these disjointed relationships, there is an ineffective transfer of information whenever a handoff occurs from one supplier in the process to another.

Three industry leaders are collaborating to change outdated design methodologies, creating open systems that support increased accuracy and efficiency in the design process to improve manufacturability and profitability. Digi-Key Corporation, NXP Semiconductor and Sunstone Circuits are putting more control in the hands of designers by giving them access to high-quality parts data, symbols and ordering/availability information. Working in partnership through the Sunstone ECOsystem®, the three players significantly reduce project turn times and associated costs.

More Information for Designers
Parts availability, pricing, and compatibility issues are now even more important to design success than traditional design rule checks, and it is becoming more and more critical to move this information upstream in the design process. In a survey of PCB designers administered by Sunstone Circuits, the typical prototyping PCB designer spends about 30 percent of the design process managing parts data, including searching for appropriate parts; for smaller design teams, the percentage can be significantly higher.

Digi-Key, leveraging the Internet, has taken electronic parts distribution to its maximal conclusion. The company stocks the entire component product lines of nearly all the major manufacturers and has no restrictions on order quantities. Although Digi-Key still produces a printed parts catalog, the company's Web site serves as the major on-ramp for gathering part specifications and for placing orders.

PCB designers typically work with a part supplier's Web site open in a browser alongside their CAD tool to research as they go. In light of this practice, Digi-Key launched a Web-query access interface in 2008, making it possible to include the inventory and pricing information from Digi-Key's Web site database in the PCB CAD tool environment itself.

What remained missing was a PCB CAD vendor to support the full Digi-Key catalog through a mechanism linking the Digi-Key part numbers to their symbols/footprints and to provide a Bill of-Materials (BOM) that easily converted into a Digi-Key order form. Such a partnership would provide greater functionality for designers and bridge the gap in the existing design process.

Bridging the Gap
PCB123, a distribution PCB design tool from Sunstone Circuits, specializes in bridging the gaps between price/performance and the processes of PCB design and manufacturing. A full-featured PCB design tool with normal schematic and layout editing roles, PCB123 also performs real-time DRC checks against a comprehensive set of design rules tailored to the Sunstone Circuits manufacturing processes; provides an autoplacer, autorouter, and net rules; presents a real-time fabrication quote for the bare board manufacturing; and allows electronic order submissions to Sunstone Circuits.

A seamless integration of schematics and layout with PCB123 connects logical and physical design. The most up-to-date version of the software includes a parts taxonomy database that allows for a rich electronic parts information model to be overlaid on an efficient organizational structure. The taxonomy frees engineers from having to learn the library structure of yet another CAD system and includes such tools as a search engine for efficiently accessing and creating parts.

The Next Step
When a semiconductor manufacturing company, such as NXP, embraces the new design dynamic as implemented here and develops a comprehensive parts library including manufacturer and Digi-Key part numbers, it seeds the PCB123 design environment with a powerful data set: a complete manufacturer's catalog, with symbols, footprints, and sufficient information to fully implement a LiveBOM query to Digi-Key.

The taxonomy structure of the system is particularly powerful when used in conjunction with additional functions. When the taxonomy is pre-populated with a large number of predefined symbols (both schematic and layout), such as the NXP library, and called out with a part number, users have an innovative resource at their disposal.

Impact on Design
LiveBOM functionality, exclusive to PCB123, monitors design progress with a BOM that stays synchronized with both the schematic and the layout views. At any time, designers can select the BOM tab and perform queries on the parts currently selected by accessing Digi-Key's real-time parts availability and pricing. By getting the total parts cost required to build the entire order, including any quantity price breaks, designers can track board fabrication costs as well as the design against a given budget for components.

PCB123 and LiveBOM also improve communication among designers as well as between the engineering team and the purchasing department. With one unambiguous specified BOM, the purchasing department is automatically ready to issue the purchase order.

Convenience and Accuracy
Through collaboration with Digi-Key and NXP, Sunstone Circuits provides PCB123 CAD users with access to ready-made, certified parts symbols from NXP and a comprehensive parts library from Digi-Key's extensive inventory. This information ensures accurate physical design, and the collaboration ensures efficient design with component availability and pricing information. Within the Sunstone ECOsystem, these functional elements provide the end-user with a turnkey level of convenience and accuracy, even on prototypes and early engineering projects.

Contact: Sunstone Circuits, 13626 S. Freeman Road, Mulino, OR 97042 503-829-9108 x555 fax: 503-829-5482 E-mail: Web: 

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