Clear communication with manufacturers can ease that queasy feeling.

You are finally finished with that very complex monster of a printed circuit board (PCB) design while enduring a very tight project schedule. Now it's time to get the design data to manufacturing for fabrication and assembly, but there is a lingering doubt in the back of your mind, an uneasy feeling in the pit of your stomach as you hand off data to manufacturing. Why? I'll explain, based on my perspective gleaned from decades of designing PCBs.

Let me start with a question: Did you collaborate with your manufacturing suppliers up front? The answer for many is typically "No!" You may have simply designed a PCB without any manufacturer involvement whatsoever, generated output files and threw the data over the proverbial wall to the manufacturer in hopes that what you designed is buildable and will work as intended. Then, when a technical query (TQ) hits your inbox, you might get upset and wonder why you're being notified that the job is on hold because the design data contain issues or are missing information that needs to be addressed before fabrication can begin. In some cases, it's not just answering with a reply of "approved to modify as suggested," but rather it requires going back and redesigning! Sadly, this happens in our industry far too often, and in more instances than you would expect.

My topic this month is design and manufacturing collaboration. In my opinion, this topic consistently needs to be addressed. It's one of the three competing perspectives for success in PCB design – which are layout solvability, performance, and manufacturability – with the goal of maximum placement and routing density, optimal electrical performance, and efficient, defect-free manufacturing. Anyone who designs PCBs needs to thoroughly understand how and why the decisions being made at the point of design will have an impact downstream, one way or another. The downstream ramifications due to poor upstream design decisions have the potential to be catastrophic in manufacturing.

At this year's PCB East, I collaborated with Summit Interconnect vice president of technology Gerry Partida on a technical session where we used comedy (or attempted, anyway) to shed light on the typical dialogue between a PCB designer and fabricator regarding design for manufacturing (DfM). We stressed to our audience the importance of having design and manufacturing collaboration throughout the entire design process. So far, this DfM comedy skit has received plenty of positive feedback, mainly because we discuss and show real-world examples.

As stated, collaboration between design and manufacturing is paramount. As a best practice, it should take place right out of the gate, starting at the project kickoff meeting. The fabrication and assembly suppliers should be included among the key stakeholders at the project table. Working with the fabricator to dial in the PCB stackup to ensure it meets PCB design requirements is key for success. From complex PCB stackups that include high-layer counts, HDI or micro HDI, multiple impedance requirements, PCB thickness requirements, current carrying capability in respective copper weights, to mitigating thermal requirements that may require exotic materials, today's complex PCBs leave no room for guessing! The potential for success significantly increases when this collaboration takes place.

Data exchange during this collaboration between design and manufacturing should be optimized. The best practice for this exchange is a format that is bidirectional, facilitating constant communication, and offers intelligence, such as ODB++ and IPC-2581. These types of data formats enable intelligent communication from engineering to manufacturing and vice versa. This includes having a manufacturing-to-engineering feedback loop. By having this in place, we enable lessons learned from manufacturing (fabrication and assembly) to be fed back to design/engineering. That bidirectional loop of communication and data exchange, especially utilizing intelligent data, has the highest potential to positively influence the design for downstream success. Don't get me wrong. The legacy methodology of supplying Gerber data and a netlist gets the job done. It has for decades and continues to do so. Just know that intelligent data exchange is the most optimal way to exchange data from engineering to manufacturing.

Having optimized, integrated, bidirectional collaboration between engineering and manufacturing minimizes errors, especially during the data exchange. Having a continuous feedback loop of lessons learned being fed back to design/engineering enables PCB design success. By implementing these best practices, you're less likely to have that uneasy feeling in your stomach or receive TQs regarding the construction and buildability of the design.

Stephen Chavez is a senior printed circuit engineer with three decades' experience. In his current role as a senior product marketing manager with Siemens EDA, his focus is on developing methodologies that assist customers in adopting a strategy for resilience and integrating the design-to-source Intelligence insights from Supplyframe into design for resilience. He is an IPC Certified Master Instructor Trainer (MIT) for PCB design, IPC CID+, and a Certified Printed Circuit Designer (CPCD). He is chairman of the Printed Circuit Engineering Association (PCEA); stephen.chavez@siemens.com.