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A Faster Path to Advanced Package Validation : Why US-JOINT Was Built in Silicon Valley
10th July 2026
On April 20, 2026 (local time), US-JOINT officially opened in Silicon Valley, USA. US-JOINT is a consortium led by Resonac Corporation, bringing together 12 companies from Japan and the United States, including materials and equipment suppliers. The initiative focuses on concept validation for next-generation semiconductor packaging, primarily for data center applications.
Why establish an industry-led consortium in the United States? What is its vision? Hidenori Abe, CTO for semiconductor materials and Executive Director of Electronics Business Headquarters at Resonac, who spearheaded the project from planning to launch, shares the intent behind US-JOINT in this two-part series.
In this first article, we delve into the background of the US-JOINT launch and explore the future of semiconductor packaging as envisioned by Resonac, a leading materials supplier.
As Scaling Reaches Its Physical Limits:
Solving the Validation Bottleneck
What challenges motivated the creation of US-JOINT?
Abe: As device scaling approaches its physical limits, performance gains are shifting decisively into the back end—specifically, packaging. With high-performance devices, thermal management becomes critical, and packaging plays a huge role there. At the same time, AI server packages are growing larger as more chips are integrated. Traditional packages were around 50 × 50 mm, but designs of about 100 × 100 mm are already emerging—making warpage management an increasingly critical challenge.
Packaging can’t be optimized through a single material or process. It requires close collaboration across materials and equipment—enabling a shift from partial optimization to true system-level optimization.
Another challenge has been the time required for concept validation. Customers often had to move test vehicles across multiple supplier sites and travel to each location in sequence, repeating the process step by step.
Hidenori Abe,
CTO for semiconductor materials
and Executive Director
of Electronics Business Headquarters at Resonac
As a materials supplier, Resonac has long invested in building and operating its own semiconductor processing capabilities, enabling material evaluation under conditions close to actual use. In Japan, this approach is embodied in the Packaging Solution Center in Shin-Kawasaki, where a prototyping line for advanced packaging is integrated with a centralized evaluation environment developed in collaboration with materials and equipment partners.
US-JOINT brings this model to the United States—providing an environment where fabless companies and hyperscalers can complete advanced packaging concept validation in one place, without the need for extensive travel or complex logistics.
Strategic Location:Silicon Valley
Why did you choose Silicon Valley?
Abe: Because this is where new ideas are born.
Fabless companies and hyperscalers—the ones driving next-gen architectures—are concentrated here. By colocating with them, we can compress the concept validation cycle dramatically—from about six months down to one.
Just having engineers working under the same roof—looking at test vehicles together, discussing ideas face-to-face—is critical for innovation. You can exchange subtle insights that are hard to communicate remotely. That’s where real innovation happens. It also gives materials and equipment suppliers early visibility into customer ideas—helping them pick up on emerging needs and refine their pathfinding.
In this industry, the materials used when a new technology takes shape often go on to become the de facto standard. US-JOINT is designed to help participants get ahead of that curve.
What kind of requests have you been hearing from U.S. customers?
Abe: They’ve been very clear:
"Don’t just show us materials—show us what they actually do in a real package."
Advanced packages are no longer simple. Take 2.5D integration with HBM (High Bandwidth Memory), for example—you’re dealing with interposers connecting logic and stacked memory, all with extremely tight interconnect lengths. Shorter interconnects enable higher performance, but you can’t fully validate it without building the actual package.
In other words, customers aren’t interested in materials on their own—they care about the performance those materials actually deliver.
2.5D package
We’ve had evaluation platforms in Japan, but for U.S.-based engineers, getting there isn’t easy—it often takes several days to a week. That made it hard to fully share performance and ideas, even when we knew what we could demonstrate. So we set out to bring that environment closer to our customers. At US-JOINT, they can access test vehicles within a short drive—about 30 minutes—and work directly with materials and equipment suppliers.
This is what makes US-JOINT unique. It brings together end-to-end validation in one place, dramatically shortens validation cycles, and enables true co-creation with customers and partners—all within Silicon Valley. It’s the kind of setup that simply hasn’t existed here.
From Siloed Optimization to System-Level Co-Optimization
What value does the consortium bring to its partners?
Abe: US-JOINT is a place where customer ideas get translated into reality—through co-creation between customers and multiple suppliers. Instead of each company optimizing its own piece, we’re aiming for system-level optimization across the entire package.
We see US-JOINT becoming a hub here in Silicon Valley—where innovation happens across company boundaries. It also gives participants early access to new ideas, and the chance to work with partners they might not otherwise connect with. We want partners to make full use of it. By working closely with customers, the goal is to establish new development approaches—and deliver real results to the industry.
Driving Innovation
Profile
CTO for semiconductor materials and Executive Director of Electronics Business Headquarters at Resonac.
Hidenori Abe leads R&D and strategy for electronic materials in semiconductors, substrates, and displays. Previously, Mr. Abe served as the head of the Electronics R&D Center and Packaging Solution Center, where he contributed to advanced packaging development through open innovation. Notably, in 2021, he directed the launch of JOINT2, a consortium targeting 2.xD and 3D packaging technologies. He also led the launch of "US-JOINT" and "JOINT3" in 2025. He received a master’s degree in chemical engineering from Tokyo Institute of Technology, Japan, and a master’s degree in the Executive MBA program from the University of Oxford, UK.
