design Best practices


Library and Design Data Management

Automating data maintenance and revision control.

In continuation of the PCB Design Best Practices series, this month we’ll dive a bit deeper into library and design data management. To be more specific, we’ll address controlling and managing company data and intellectual property.

In general, most companies function in the same manner when it comes to electronic systems design, at least from an outsider’s perspective, and PCB design is the same no matter what company you work for, what culture you belong to, what tool(s) you use, and what, if any, product lifecycle management (PLM) system you use. The difference from company to company is how people internally operate when it comes to library and design data management.

Today, we have engineering teams that work at the same location, interacting in person, and those that work remotely, sometimes spread across the globe. And of course there are combinations of these collaboration scenarios. Throughout my career I have worked in all of these environments. So, I’ve a good deal of experience when it comes to the different ways companies address library and design data management.

The library is the foundation of every PCB design. Accuracy, correctness and data integrity are key to long-term success. The industry best practice for library management is to utilize a type of electronic data management (EDM) system. From part creation through end-of-life, library data can be managed, maintained and controlled utilizing a tool with this type of automation.

Why is this best practice? The best designer in the world can design the simplest PCB possible, but if a library part is designed incorrectly and then implemented in a design, the outcome can be catastrophic. I have firsthand experience in powering up a very complex printed circuit assembly (PCBA) that contained a high pin-count BGA, where that BGA library part was created with the incorrect pin numbering scheme, which was not caught during the part creation process. Talk about instant overheating, resulting in catastrophic circuit burn/blow up!

A great deal of time was lost due to this error because the project was not able to move forward as planned. Then, additional engineering design time was required to fix and update the library part and redo the actual PCB design layout. To make matters worse, this bad BGA part was being used in another design. Luckily it was caught in the early stages of that design, so no major re-routing was necessary. These issues happened because manual efforts introduced human error.

The industry best practice is to use an EDM solution along with a tool capable of utilizing automation and design-for-manufacturing (DfM) checks to create, verify, and validate complex parts before they are released into a system. I have experienced similar issues, like library part updates, as well as an incorrect part number listed on a bill of materials that did not match what was in the layout of the PCB. I have heard many similar, if not worse, stories from industry colleagues regarding poor library data management, library parts being created incorrectly and not caught until after the fact, or someone ordering and purchasing the wrong parts, causing assembly issues and project delays downstream.

When it comes to managing design data, the industry best practice is to utilize a PLM system. This methodology has the highest potential for long-term success in managing your design data. Implementing and utilizing a true PLM system typically comes at financial cost, with more overhead to maintain the PLM system versus a manual approach. However, the latter provides very little or no control when it comes to maintaining the integrity of design data and no way to restrict or control who can access and or modify it. I’ve also experienced my fair share of the legacy approach of placing design data on an internal, open server where anyone can access and modify data, as well as having to manually conduct “where used” inquiries for individual components and specific PCB and PCBA versions. Talk about time consuming and all the potential for things to go wrong!

Although I have had success with this manual methodology, I’ve also had bad experiences. Like when an incorrect version of a PCB was fabricated due to incorrect versions of design data being sent to fabrication. Another issue I have experienced was when the engineering team started on a project with a particular version of a design that was thought to be the latest, but it wasn’t, because someone accidently deleted the final released production version of the design from the server. Then, later, someone replaced the released design with a previous older version, not realizing or knowing that there was a small, yet critical difference in that newer production version of the design. Sadly, these types of issues still happen today with this legacy approach.

The return on investment of a true PLM system is very high and significantly increases the ability to manage and maintain the integrity of design data and control access to it. Utilizing a PLM system along with integrated tools increases the potential for an optimized digital thread during the PCB design process. But it’s more than that. It’s having the ability to control and maintain the integrity of your design data, specify who can access or modify the design data, and view and make inquiries regarding revisions and “where used,” from PCBs to PCBAs down to individual components and the respective suppliers.

When it comes to industry best practices for library and design data management, the legacy manual approach is not good enough anymore. Using an EDM solution and a PLM system is the best practice for managing library and design data. Article ending bug

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); Chavez will speak at the PCB West technical conference in September in the Santa Clara (CA) Convention Center.