The Evolution of the Lid: Material Innovations, VC and Microchannel for AI Packages

11:30 am - 12:00 pm

As AI accelerators and HPC clusters push the thermal design power (TDP) into the multi-kilowatt range toward the 2000W threshold and beyond, the Integrated Heat Spreader (IHS)—commonly known as the "Lid"—has evolved into a critical thermal gateway

This extreme heat flux not only threatens logic and HBM performance but also jeopardizes the signal stability of next-generation Co-Packaged Optics (CPO). Severe thermal-optical effects can cause wavelength shifts, and traditional single-piece lids induce chip warpage during thermal cycling, which leads to non-uniform Bond Line Thickness (BLT), poor TIM coverage, and critical degradation of optical alignment accuracy. This presentation re-centers the "Lid" as the protagonist of advanced thermal management by exploring next-generation architectures, specifically Vapor Chamber (VC) Lids and Microchannel Lids (MLCP).

By precisely engineering the Lid’s geometric structure and surface profile, we can effectively counteract chip warpage, minimize interfacial stress, maximize TIM1 efficiency, and safeguard CPO optical alignment. Furthermore, integrating microchannel cooling directly into the Lid creates a "zero-interruption" thermal path that allows the coolant to directly contact the heat source, eliminating the secondary TIM layer (TIM2).

The presentation also examines the integration of cutting-edge Copper-Diamond (Cu-Diamond) composite materials into the Lid design. Boasting immense thermal conductivities exceeding 500 W/mK and excellent CTE matching.

Finally, we look toward future two-phase liquid cooling architectures. By utilizing the phase change process and latent heat of vaporization, these ultimate cooling solutions are positioned to support extreme compute chips consuming power.

Key Technologies Covered

Extreme AI heat flux thermal management (Kilowatt-range / >2000W)
Advanced Lid (IHS) architectures (VC Lid and Microchannel Lid)
Lid geometric optimization for chip warpage control
Co-Packaged Optics (CPO) thermal-optical effect mitigation and alignment protection
Thermal Interface Material (TIM1) performance and BLT optimization
Copper-Diamond (Cu-Diamond) metal matrix composite Lids
Two-phase liquid cooling architectures (Two-phase cold plates )

Featured Speakers

Dr. Jenda Yeh

Vice Director, Jentech Precision Industrial Co., Ltd.

Dr. Jenda Yeh is the Deputy Director of the Advanced Tech. Development Center at Jentech Precision Industrial Co., Ltd., where he leads the strategic R&D of next-generation thermal management solutions. He earned his Ph.D. in Mechanical Engineering from National Central University, Taiwan in 2008, specializing in micro-heat exchanger technology and heat transfer enhancement techniques. His academic depth provides the theoretical foundation for solving extreme thermal challenges in today’s escalating power density environments.

With nearly two decades of expertise, Dr. Yeh’s career began in specialized thermal R&D roles (2008–2014) before joining Jentech in 2014. Prior to his current position, he served as the Deputy Director of the Thermal Module Product Division, where he successfully spearheaded the mass production of integrated server-level liquid cooling modules. This extensive industrial experience allows him to seamlessly bridge sophisticated thermal theory with Jentech’s world-class precision machining & high-volume manufacturing infrastructure.

A prolific innovator, Dr. Yeh holds over 30 patents across the United States, Taiwan, and China, primarily focused on invention patents that advance cooling architectures. His technical leadership has been instrumental in the development of production-ready Vapor Chamber Lid and Microchannel Lid, as well as other next-generation cooling technologies for AI and HPC chipmakers. By combining his expertise in heat transfer enhancement with Jentech’s robust capabilities in Brazing, Diffusion bonding, precision machining and stamping, Dr. Yeh provides the semiconductor industry with reliable Total Solutions to overcome the critical thermal bottlenecks of heterogeneous integration.