Happy’s Tech Talk #44: Memories of the ‘Mystery Systems of the East’
The Right Approach: Electro-Tek—A Williams Family Legacy, Part 2
Alpha Insights, Performance by Design: Understanding Heat at the Core of Every Design
UHDI Fundamentals: An Overview of UHDI Substrate Materials and Vias
November 13, 2025 | Anaya Vardya, American Standard CircuitsEstimated reading time: Less than a minute
The rapid proliferation of 5G/6G communications, Internet of Things (IoT), high-performance computing (HPC), AI, and medical electronics has driven the need for increasingly compact, high-performance circuit packaging. UHDI, defined by feature sizes well below traditional HDI, addresses these demands by enabling ultra-fine lines, dense via interconnects, and embedded passive functionality. Understanding the materials and layering strategies in UHDI is essential for advancing both manufacturing and application design.
Substrates and Dielectrics
UHDI technology represents the next evolutionary step beyond traditional HDI PCBs. Characterized by sub-15 μm line/space resolution, stacked and staggered microvias, and ultra-thin dielectric layers, UHDI enables miniaturization, high-frequency performance, and integration of advanced functionalities. This article provides a high-level overview of the materials and layer structures that underpin UHDI, and highlights their properties, advantages, challenges, and ever-increasing applications across every market sector.
Dielectric Substrates
UHDI requires dielectric layers as thin as 10–15 μm, enabling short microvia depths and multiple build-up cycles (sequential lamination). The thinness supports high interconnect density while maintaining mechanical reliability.
To continue reading this article, which originally appeared in the November 2025 edition of Design007 Magazine, click here.
Share on:
Testimonial
"Our marketing partnership with I-Connect007 is already delivering. Just a day after our press release went live, we received a direct inquiry about our updated products!"
Rachael Temple - AlltematedSuggested Items
Advanced Electronics Packaging Digest: Third Issue Arrives November 17
11/12/2025 | I-Connect007The third issue of Advanced Electronics Packaging Digest launches Monday, November 17. This issue continues AEPD’s mission to deliver forward-looking analysis and insider perspectives on the technologies reshaping advanced electronics packaging. Among the highlights is a review of IMPACT 2025, where discussions on component-to-system-level integration took center stage as experts explored the challenges and breakthroughs driving advanced packaging technologies.
I-Connect007 Editor’s Choice: Five Must-Reads for the Week
11/07/2025 | Marcy LaRont, I-Connect007In electronics industry news, my picks start with Pete Starkey’s review of EIPC’s latest Technology Snapshot webinar. With all eyes on Europe as a pressure lever for ESG worldwide, Pete’s coverage is a must-read. Next, I want you to check out the new column by Leo Lambert on EPTAC, who provides a solid and complete overview of UHDI from concept to assembly.
Learning With Leo: UHDI—The Next Leap in PCB Manufacturing
11/05/2025 | Leo Lambert -- Column: Learning With LeoHigh density interconnect (HDI) technology has been a cornerstone of miniaturized electronics since Hewlett-Packard introduced the first chip-scale implementation in 1982. Over time, HDI processes became central to organic flip-chip packaging in the semiconductor industry. Today, the convergence of IC substrates and system-level PCBs has accelerated the adoption of UHDI.
UHDI Fundamentals: UHDI Technology and Automated Inspection
11/03/2025 | Anaya Vardya, American Standard CircuitsFollowing up on the last article on integrating ultra high density interconnect (UHDI) PCB technologies and Quality 5.0, here we will do a deeper dive into the automated inspection component. UHDI applications demand extreme precision, with line/space dimensions below 25 µm and microvias below 30 µm. Automated inspection systems are essential to achieving the defect-free fabrication required at these scales, and legacy automated inspection systems are becoming obsolete and ineffective.
On the Line With… Ultra HDI Podcast—Episode 7: “Solder Mask: Beyond the Traces,” Now Available
10/31/2025 | I-Connect007I-Connect007 is excited to announce the release of the seventh episode of its 12-part podcast series, On the Line With… American Standard Circuits: Ultra HDI. In this episode, “Solder Mask: Beyond the Traces,” host Nolan Johnson sits down with John Johnson, Director of Quality and Advanced Technology at American Standard Circuits, to explore the essential role that solder mask plays in the Ultra HDI (UHDI) manufacturing process.