|Manufacturing success depends on replacing outmoded design and fabrication models. |
The PC board design cycle process can be divided into four capabilities quadrants: Knowledge; Tools; Libraries; and Manufacturing. At Sunstone, we liken these quadrants to an engineering ecology, or ECOsystem.
For manufacturers of printed circuit boards and prototype boards the need to merge CAD/EDA design technology with the manufacturing process is greater than ever before. No longer can a typical EDA or design service business model influence the entire supply chain. EDA companies are less and less able to direct the direction of the PC board design industry. It's becoming increasingly clear that design teams and supply chain vendors must take control of the PC board design processes, from idea to delivery. To date, CAD and EDA technology has consistently promised convenience and productivity for design engineers. Yet, shrinking geometries, electronic component advances and design complexity have instead created a persisting chasm between increased design and production that has not yet been adequately addressed, let alone solved. The process is, in a word, "broken."
Innovative, industry-leading electronics manufacturers are using a few key design methodologies and tool sets to fix this broken process and improve their design performance:
- Design integrity metrics in order to measure performance.
- Rules-driven automation in order to maintain design integrity.
- Fabrication and assembly analysis strategies.
- Collaboration/visualization processes (Aberdeen Group, PC board DI report).
A Different Approach
As in any ecosystem, strong specialty vendors have staked out one of these key capabilities quadrants and built their value proposition around being the best in their specialty. This territorialism created long-standing communication barriers between the quadrants. But today's pressures mean that a design team must tear down the communication barriers between these four design cycle quadrants. Tighter integration between design and manufacturing environments can only result in better communication, fewer design turns and lower development costs overall. Large, well-funded electronics corporations have understood this, and have poured years worth of development into building internal design systems and in-house fabrication facilities with this very goal in mind. The average engineering team, on the other hand, had no way to locate cost-effective, low-barrier-to-entry design environments, thereby creating a tools gap yet to be filled.
For design teams striving for competitive performance, access to an open design environment that embraces the entire supply chain (suppliers, fabricators and service providers) has long been a strategic goal. This environment would be use key tool sets that encourage collaboration between designers, design teams, and companies along the PC board manufacturing supply chain. In an ideal world, this design environment would utilize a pay-to-use model; tools would be free to use and vendors would be paid when the job is submitted to their firm for delivery. Tools would provide, and make use of, Software Developer's Kit (SDK) interfaces to encourage collaboration and design integrity at the same time. Finally, this environment would be open — to encourage companies and individuals to build new, creative tools inside the environment. Sunstone's ECOsystem delivers on this ideal pay-to-use vision for design teams.
Rules Driven Automation
Rules-Driven Automation (RDA) is a key piece to a successful ECOsystem. For a successful Design for Manufacturing (DFM) philosophy, design teams need design rules that describe and enforce the fab's manufacturing capabilities. Used from the beginning of the design process, these rule decks ensure that designers can make the most informed placement and routing decisions in real time, when design tradeoffs are easiest to manage and errors easiest to correct.
A central component to RDA must be a design tool that offers true integrated, modeless schematic and physical design, and pre-defined design rules that enforce manufacturing capabilities from the fabrication supply chain. Current PC board design tools provide mechanisms for defining the DRC rules for a particular PC board fab, but these DRC features are underutilized in the industry. Fabs and tool vendors must cooperate to deliver rule decks that designers can use to drive their design decisions as soon as they select their fabricators.
Rules Driven Automation must extend up and down the supply chain as well. Vendors along the supply chain will increasingly need to access the design database directly. Software Developer Kits allow vendors and individuals to write plug-in modules to extend functionality. An innovative assembly house, for example, might develop a tool that makes use of the footprint data direct from the design to optimize placement routing to their specific machinery, or to consolidate parts planning across multiple customers. Assembly houses — and other supply chain vendors — can realize additional efficiencies through an ECOsystem's closer access to the designer's intent (via the design data itself), and by actively providing useful rules that guide designers to a more manufacturable design.
As the previous examples show, the supply chain will increasingly work from the core design file generated by design tools. Rather than relying on artwork files, like Gerbers, it will be necessary for companies in the PC board fab supply chain to start seeing the native design files as the encapsulation of the order itself, building interfaces to extract the data they need directly. In today's design environment, each tweak to the design throughout its life cycle requires regeneration of the artwork, new netlists, new bills of materials, etc., which then must be distributed throughout the supply chain. All these specialized output file formats increase the possibility of building an incorrect or out-of-synch version of the customer's PC board.
Another key to improving design integrity is incorporating a design editing tool that works on a single network database, allowing for quick, iterative movement from schematic to layout as the design progresses. With such a tool, Designers can make decisions regarding manufacturability during the initial layout processes, shortening debug and repair time and lowering overall design costs.
By creating an open environment in which vendors manage their own interfaces into a common design format, the integrity of the design intent is preserved and maximized throughout the supply chain. Like any real-world ecosystem, vendors who deliver sub-par work during their portion of the fab cycle will find themselves non-competitive.
There has been, traditionally, a chasm between the separate processes of design and manufacture. This chasm is illustrated by the industry's continued reliance upon aging file formats (such as Gerber, IPC-356, etc.) to transfer PC boards "over the wall" to the manufacturing process. Once the design is output in Gerber, however, the design loses all the electrical or network knowledge in the design file. And yet, some manufacturing steps — such as flying probe test — rely on the now-missing original electrical network for reference. PC board fabricators often resort to reverse-engineering the netlist from the Gerber file, a difficult and sometimes error-prone process. The knowledge left behind by current translation steps hurts the supply chain's ability to add any more innovative services that require design knowledge.
By looking to the design to act as the order itself, supply chain providers, such as assembly houses, can access everything from net information, to a parts list, to centroids for assembly. SDKs enable users to develop new tools for design analysis, and allow the supply chain to build simpler, more knowledge-rich interfaces that reduce turns for the user and increase knowledge transfer for the supply chain. These new interfaces create fabrication efficiencies that translate into faster and fewer design turns for designers, and in higher operating margins for fabricators.
Beyond the design environment, web-based design hosting also plays a critical role in improving fabrication & assembly. In an open supply chain environment, for example, web-hosted design files will allow procurement team members to optimize and schedule production runs to align with changing production forecasts. Procurement professionals will be able to submit their designs for evaluation and quote at a number of fabrication houses, allowing the design teams to make trade-offs on lead times, price, and how much risk they're willing to take with the capabilities of a particular vendor. For design teams and fabs, this closer communication will delay many JIT-minded customers from moving overseas with production — certainly until much later in the product's life cycle — and this could help to stem the wholesale migration of PC board fabrication to overseas facilities.
By looking at the design environment differently, a pathway to a solution emerges for companies striving for Best in Class performance. Open Source and free-distribution business models have proven that commercial grade software can be made available at no upfront cost to the user.
Nevertheless, PC board design teams operating outside the environments built by the well-funded, industry leading electronics manufacturers must drive the PC board industry to bring the process of design and fabrication closer together.
Supporting the status quo through traditional EDA software development models inhibits this Design-to-Fabrication integration unless you have deep internal resources to spend on an enterprise integration project. Sooner or later, the PC board design & fabrication industry will be forced to address this chasm; Sunstone's ECOsystem is choosing to bridge this chasm today. Engineering teams looking to improve their design methodologies without diverting large amounts of their existing R&D budget to tools, should carefully investigate alternative environments such as free-for-distribution or open-source models. It's these innovative, collaborative companies that are pushing their ability to collaborate up into the earlier stages of the design cycle, thereby becoming the designer's partner, not just a point-solution vendor.
For more information, contact: Sunstone Circuits, 13626 S. Freeman Rd., Mulino, OR 97042 800-228-8198 or 503-829-9108 Ext. 555 fax: 503-829-5482 E-mail: firstname.lastname@example.org Web: http://www.sunstone.com