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CAMBRIDGE, MA – Draper has developed a predictive design tool that has been tested and validated to show it can predict material failure rates and help determine design requirements for printed circuit boards and similar products.

In testing, engineers found that the tool accurately predicted methods to reduce and eliminate the initiation and propagation of laminate cracks on a PCB.

The study, prepared for IPC Apex Expo 2022, was conducted by designing printed circuit boards, using different configurations and materials, and subjecting the boards to environmental stresses and other tests. Using the principles of predictive design, engineers developed data sets to guide them. One data set included testing of PCB materials for attributes such as fracture toughness and thermal conductivity. Another set included detailed design features of the PCB itself.

With the data, the engineers developed a virtual test bed – a finite element analysis computer-aided model – and used it to run scenarios of various PCBs. The FEA model successfully predicted a 50% decrease in internal stress that would reduce or eliminate PCB laminate cracking.

By adjusting the type of materials and design layouts of a PCB, the team was able to reduce the number, types, and severity of board defects when minor design changes were made.

Draper’s Wade Goldman led the team.

“The FEA model allows us to move attributes around to reduce the number and likelihood of cracks in the PCB,” Goldman said. “If every design works as expected, PCB designers and manufacturers are no longer limited to trial and error manufacturing. Instead, they can spend their time evaluating design changes that might be helpful in reducing defects and not changing their processes. »

The model comes at an opportune time for the tech industry, Goldman added. “Nowadays it’s all about designing higher density PCBs. As a result, the interconnects are getting smaller, which introduces brittleness, and the industry is making more material choices to run the higher-density interconnects. You need a predictive design tool to support this effort. »

The predictive design tool should provide PCB designers with a model to determine design rules for future products.

“With this new capability, we have taken a big step towards being able to manufacture higher quality printed circuit boards.”

Register now for “DFM Best Practices for Consulting Engineers,” a new three-hour webinar from Susy Webb, CID. Coming February 22. www.pcb2day.com