Description:
This invention integrates a crystalline diamond- or sapphire-backed heat spreader directly onto silicon wafers prior to chip fabrication, paired with a sealed fluid chamber that delivers direct-to-chip liquid cooling without thermal interface materials. The result is a low-resistance, high-efficiency cooling path that improves reliability, reduces energy and water use, and simplifies packaging for AI and high-performance computing systems.
Background:
High power microelectronics in AI, HPC, and advanced gaming generate extreme, uneven heat flux that existing air and liquid solutions struggle to remove due to interface losses, bonding stresses, and packaging complexity. Thermal interface materials and post fabrication heat spreader bonds add resistance and reliability risks, especially in multi-chiplet assemblies, limiting performance and increasing cost. The proposed solution has the potential to reduce energy and water consumption when applied to large-scale data centers.
Technology Overview:
The approach deposits a crystalline heat spreading layer such as diamond or sapphire on the backside of silicon wafers prior to device fabrication, forming a molecularly bonded, high conductivity path through the die. After fabrication, a customized package lid incorporates a sealed fluid flow chamber that brings liquid or two-phase coolant into direct contact with the back-coated die surface while maintaining full electrical isolation. A package frame and filler create a common chamber floor across multi-chiplet assemblies, tolerating surface nonuniformities and eliminating post fabrication heat spreader bonding or chip redesign.
Advantages:
• Very low thermal resistance through wafer-integrated diamond or sapphire spreader
• Eliminates thermal interface materials in the primary heat path
• Avoids post-fabrication bonding to improve reliability
• Fully compatible with standard silicon process flows
• Direct-to-chip cooling with electrical isolation from the fluid
• Supports multi-chiplet packages and different chiplet heights
• Reduces system cost via higher cooling efficiency and simplified assembly
Applications:
• High-performance AI and HPC accelerators in data centers
• High-end consumer and professional CPUs and GPUs
• Ruggedized embedded computing for aerospace and defense
• Telecommunications and edge computing modules with dense packaging
• Control electronics for quantum and other precision research systems
Intellectual Property Summary:
• United States – 63/893,597, Provisional, Filed 10/06/2025, Status: Filed
Stage of Development:
First-order models.
Licensing Status:
This technology is available for licensing.
Licensing Potential:
Ideal for semiconductor manufacturers, data center operators, and advanced cooling system developers seeking efficient, scalable, and sustainable thermal management solutions for high-power chiplets.
Additional Information:
Thermal modeling results and packaging integration details available upon request.
Inventors:
Kanad Ghose, Srikanth Rangarajan, Bahgat Sammakia