Issue link: https://iconnect007.uberflip.com/i/1449048
FEBRUARY 2022 I DESIGN007 MAGAZINE 39 and verified capabilities, "manufacturing" in the acronym DFM, is a moving target based upon unknown capability. Project schedules are always behind. We're oen faced with a compression of design tasks, design scope, and design technology, to the point where we're seeing that all these tasks are becom- ing blurred without answering the question, "Who is going to be the board supplier?" on the front end. Due to increasing differences in supplier capability, even the term design for manufacturing is being reconsidered. We're going so fast with technology changes, and the requirements for electronics, that we're having to consider design with manufactur- ing. But until then, the traditional injustice of a designer not knowing where their boards are going to be manufactured is still real. We must push back against that. Matties: Bob, what's your reaction to what Happy had to say? Bob Tise: I think Happy's got a great point. I worked at HP for four or five years, and it was a pretty good experience. It's also very structured. ey're big enough that they need structure. At Sunstone, I put together a set of requirements before I'd even talked to a customer about doing design. en, if they were willing to meet them, it was pretty rigid, because in order to have a successful design, you have to have certain things. Number one, they must supply you with a completed bill of materials and the schematic involved, let you know what they need the design to do, and tell you about anything critical. You must have the entire design thought out and defined before you ever start doing the lay- out. I was usually dealing with one person. A lot of times, they had a hard time understand- ing that. en, once you pick it up, you must know the board size and the keypads and all the things that go into that, to define the scope of work. Again, if you don't have that, you're winging it and it's probably not going to fit, or they don't care. If they don't care, that's about a 30% hit. Dack: From a design perspective, we must con- sider all the stakeholders in the process. Gone are the days when a designer sat down in a vacuum with an engineer and designed a suc- cessful board. What we always say is, "What we breadboard in the lab is easy, but go try to get that manufactured and make a million of them." It's very difficult, unless you involve all the stakeholders. We define these milestones as constraints. PCB designers must take into consideration all the constraints of all the stakeholders. One possibility is the customer. e con- sumer is concerned about cost, but how much is this product going to cost overall? How much will this added cost affect profitability? Complexity adds cost. When we talk about a circuit board, an electronic assembly, we're bringing together hundreds, if not thousands of different parts. You've got 1,000 exponen- tially more complex scenarios that you must throttle, which means a designer sometimes must rob Peter to pay Paul in order to get a success story. Holden: "How big is the printed circuit board?" is actually a milestone, because there's a tradeoff. Which size should they be? I'm focused on cost, minimizing weight in laminate, things like that. at's a milestone, because the question right aer that is "How many layers—power layers, ground layers, and signal layers?" PCB designers must take into consideration all the constraints of all the stakeholders.