PCBgogo

Maury Wright spend a good portion of his time meeting with companies in the EOEM (electronics-original-equipment-manufacturing) market, and most of those meetings are with semiconductor vendors due to the vast number of such companies. But on a recent trip to the Northwest, Maury Wright spent time with some different types of companies—two of which are involved in the prototype-PCB (printed-circuit-board) area. The meetings got me thinking about how engineers use prototype PCBs in the design process. Maury will offer up a few things he heard. Maury Wright was also hoping that you will respond in the Feedback Loop comment section located alongside the online version of this article and tell us and your fellow readers how you use prototype PCBs.

First, Maury met with LPKF Laser & Electronics. LPKF makes equipment that allows design engineers to quickly make their own prototype PCBs. A number of years ago, EDN ran a feature on this technology that you might find interesting: See "Prototyping tools transform design dreams into reality." LPKF offers computer-controller PCB plotters along with milling machines and plating systems. For as little as $10,000, you can buy the gear you need to build PCB prototypes, although the price can escalate based on your needs for multilayer and SMT (surface-mount-technology) support. The company even offers laser-based plotters for small production runs.

LPKF President Stephan Schmidt claims that design engineers drive the purchase of most of the company’s systems due to the need for building prototypes during the design process. Schmidt doesn’t suggest that techniques such as simulation aren’t valuable. But he claims that designers often yield higher quality and better performing systems when they can do a series of prototypes to test the system architecture and design.

Even if you don’t have an immediate need for a prototyping system in your lab, you might still want to request a copy of the LPKF catalog. In the back of the catalog, the company offers a technical guide on PCB manufacturing. Although the catalog presents the information relative to LPKF products, there is also good general information, including sections on design for microwave and RF systems and on SMT designs. LPKF is also worthy of praise for its efforts to encourage engineering education. The company provides refurbished gear to high-school pre-engineering programs.

Later in my trip, Maury met with Sunstone Circuits, a manufacturer that specializes in prototype PCBs. Originally, Sunstone was in the production-PCB business, but almost all of the production-PCB business has moved to Asia. Sunstone allows designers to specify and order PCBs online and often can deliver products in two days. The company also offers free PCB-design software.

Maury would have guessed that most designers ordering prototype PCBs would not order the PCB in the target-system form factor. Maury is accustomed to seeing reference designs and development boards with extra connections that offer access to interconnects between chips and to test ports. But Sunstone claims that 80 to 90% of its orders are in the target-system form factor. Rocky Catt, Sunstone’s executive vice president and chief operating officer, claims that some designers will build prototype PCBs with more layers than the production board will use. For the prototype, the designer might rely on an autorouted layout that could lead to extra layers, whereas for the production board, the designer will hand-optimize the board to minimize the number of layers.

How do you use prototypes? Do you prototype only challenging parts of a system design? Do you iteratively build prototype PCBs to tune a design? How should EDN cover PCB design? Are we delivering information you need? You can certainly e-mail me or call me with answers, but by posting your comments online, your fellow readers can benefit from your thoughts as well.