Issue link: https://iconnect007.uberflip.com/i/1426508
38 DESIGN007 MAGAZINE I NOVEMBER 2021 Feature Interview by the I-Connect007 Editorial Team Over the years, there has been a lot of focus on the "design for," primarily design for man- ufacturing (DFM) and design for assembly (DFA). For many designers, design for test (DFT) is an aerthought, if it even enters the conversation during design planning. e I-Connect007 Editorial Team recently asked William Webb, technical director of test soware provider ASTER Technologies, to discuss the company's approach to test, the technological advances that are driving changes in DFT, and what PCB designers need to know to plan their DFT strategies. Nolan Johnson: Planning for design for test must have some influence on what happens on the manufacturing floor in test and inspection. And, of course, the manufacturers see all that equipment as the cost of doing business. It's not a value-add. Does this match up with your perspective? William Webb: Yes, it does, and you're right. A lot of times, it can be hard to make a DFT tool sale to an EMS company for the reasons you said. We have many EMS customers, but in ini- tial discussions they sometimes don't see the value straight away. DFT can be seen as just a cost to them, whereas an OEM has more inter- est, if you will, in buying a tool like ours. If you have a test escape that you don't know or understand, and it's giving you a produc- tion yield hit, then you've likely got prod- uct coming back as a field return, and that's a high cost to the EMS provider. So, the EMS provider can use a tool like TestWay to iden- tify devices that are not covered properly, or it helps you identify your DPMO (defects per million opportunities) that you weren't aware of, which is leading to a yield hit and will ulti- mately be a cost for the EMS provider. Once we've explained this benefit to EMS compa- nies, they usually understand the potential sav- ings. It's then easier for them to put a return on investment (ROI) together for management, to show that they can easily pay for the tool if DFT and Test Strategies Shouldn't Be an Afterthought