Cold Sprayed Copper-Diamond Composites for Thermal Management of Semiconductor Packages
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2025-01-14 |
| Journal | IMAPSource Proceedings |
| Authors | Wenhao Li, Feras Eid, Yoshihiro TOMITA, Johanna Swan |
| Institutions | Intel (United Kingdom) |
Abstract
Section titled āAbstractāThermal management is key to enabling increasingly powerful chips and heterogeneous integrated 2.5D/3D systems. Composite materials with high thermal conductivities that can be placed at different levels of proximity to the die provide new solutions for heat dissipation. Here we report the fabrication of thick copper-diamond composite films using cold spray, which is a high-throughput, low-thermal budget deposition technology. In cold spray, feedstock micro powder is accelerated in a specially designed nozzle by a heated pressurized gas and adheres to the substrate upon high-speed impingement. This process achieves higher deposition rates than other methods used in semiconductor manufacturing (such as electroplating). It also produces films which are denser and much less porous than ones produced by conventional thermal spray techniques. In this work, we first use process and thermal simulations to determine the requirements of the micro diamond powder feedstock, including the diamond core size, metal clad thickness, the core-clad interfacial resistance and volume fraction to enable the cold spray of copper-diamond composites with thermal conductivities that are higher than copperās. Subsequently, we perform systematic characterization of the diamond powders from several suppliers, including the purity, metal oxygen content, particle morphology and metal-clad adhesion. This characterization reveals the challenges of meeting all the specs using currently available diamond powders . Finally, we cold spray copper-diamond composite films on a variety of substrates with tunable thicknesses between 100um -2 mm, achieving a thermal conductivity that is approximately 10% higher than cold sprayed pure copper. Further improvement of the thermal properties relies on continued innovation in powder surface modification and powder packaging/shipping methods.