Just Ask Happy: Stacked Microvia Reliability Issues

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We asked for you to send in your questions for Happy Holden, and you took us up on it! The questions you've posed run the gamut, covering technology, the worldwide fab market, and everything in between. Enjoy.

Q: Stacked microvias look good on paper, but they may have reliability problems. What are the best rules for designing stacked microvias to ensure a reliable PCB?

A: The current best practice is stacking no more than two layers, and then moving over for the next buried or blind via or stacking two layers there. The stacked vias should never be stacked on any buried vias.

An IPC committee is currently testing various stacked via configurations to have a comparison for reliability and testing coupons and design. Hopefully, they will also get at the root cause of why stacked microvias are failing at their interface.

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08/06/2019 | Pete Starkey, I-Connect007

The Microvia Summit on May 16 was a special feature of the 2019 event in Baltimore, since microvia challenges and reliability issues have become of great concern to the PCB manufacturing industry. It provided updates on the work of members of the IPC V-TSL-MVIA Weak Interface Microvia Failures Technology Solutions Subcommittee and opportunities to learn about latest developments in methods to reveal and explain the presence of latent defects, identify causes and cures, and be able to consistently and confidently supply reliable products.

07/25/2019 | Pete Starkey, I-Connect007

The IPC High-Reliability Forum and Microvia Summit covered a broad range of topics related to reliability and provided interactive opportunities to share expert knowledge and experience in determining and understanding the causes of failure and selecting the best design rules, materials, processes, and test methods to maximise product reliability.

08/02/2017 | Craig Armenti, Mentor Graphics

Deriving the physical constraints and fatigue issues for a design prior to manufacturing is essential to reducing board failure and thereby improving product quality. In harsh environments, fatigue can be responsible for up to 20% of failures. Customers have come to expect reliability across the industry spectrum no matter where actual production occurs. Reliable products have less risk of failure, less field returns and less warranty claims, all of which contribute to higher profitability. It is a given that every product is expected to fail at some point, however premature failures can be mitigated through proper design with attention to potential issues due to vibration and acceleration.