Issue link: https://iconnect007.uberflip.com/i/1190860
52 DESIGN007 MAGAZINE I DECEMBER 2019 Nearing Product Release Once you get close to product release, your boards need to be pretty well-defined. At this stage, your documentation should include a full set of notes with specific callouts, mate- rial specification, silkscreen and solder mask, copper weight and plating thickness, test and inspection requirements, and so on. As you move into the final rounds of development and then production, you'll need to add more doc- umentation, including detailed manufacturing requirements and inspection criteria to meet commercial standards. At this stage, you need full fabrication notes because quality is critical here; missing important documentation can be expensive and severely impact the quality of your final product. But Wait, There's More! Depending on what you're designing, you might need even more documentation. If you're designing for the transportation, medical, de- fense industries or another highly regulated in- dustry, there's a lot more documentation you'll need. In these scenarios, the sky's the lim- it in terms of what standards you might have to meet and the accompanying documentation you need to supply. Any of the following may apply to the specific product you're building: destructive testing, IPC-6012 Class 3 or Class 3A, ITAR, FDA requirements, etc. When you get into these areas, your notes may take up a full sheet in your drawing package and refer to de- sign and manufacturing specifications that are hundreds of pages long. These documents can cover not only quality manufacturing process- es, but also things like materials sourcing, re- cord keeping requirements, test specifications, labor and purchasing, ethics, handling, pack- aging, and any number of standards you may have to meet to bring your product to market. Create the Right Notes for the Right Stage of Your Design As your boards get more complex and com- plete, so should your fabrication notes. And while documentation itself is important, it is equally critical to create the right level of docu- mentation for the development phase you're in. Often, developers add a full documentation set along with an order for low-cost test boards. PCB manufacturers can't deliver the same level of service for inexpensive test boards as they do for production boards, and it will save you time and money to set your expectations—and documen- tation—appropriately for what you're ordering. Some prototype or run-as-sent services will automatically delete anything that isn't a Ger- ber file, and others might see pages of fabrica- tion notes for a batch of test boards and stop the order to review the notes and call or email you to discuss what the need really is. Often, if someone really just needs some test boards but sent along a full set of canned fabrication notes, the end result is that the order for test boards is delayed while the PCB manufacturer vets the requirements with the customer. To help ensure that your PCB manufacturer can get the boards you need in the timeframe, and at the price point you need for your stage of product development, create and send only the fabrication notes that are relevant for that stage. You'll save yourself time and money and get your product to market faster. DESIGN007 Bob Tise is an engineer at Sunstone Circuits, and Matt Stevenson is the VP of sales and marketing. To read past columns or contact Tise and Stevenson, click here. Bob Tise Matt Stevenson