Lightweight diamond/Cu interface tuning for outstanding heat conduction

Abstract

With rapid developments in the field of very large‐scale integrated circuits, heat dissipation has emerged as a significant factor that restricts the high‐density integration of chips. Due to their high thermal conductivity and low thermal expansion coefficient, diamond/Cu composites have attracted considerable attention as a promising thermal management material. In this study, a surface tungsten carbide gradient layer coating of diamond particles has been realized using comprehensive magnetron sputtering technology and a heat treatment process. Diamond/Cu composites were prepared using high‐temperature and high‐pressure technology. The results show that, by adjusting the heat treatment process, tungsten carbide and di‐tungsten carbide are generated by an in situ reaction at the tungsten–diamond interface, and W–WC–W2C gradient layer‐coated diamond particles were obtained. The diamond/Cu composites were sintered by high‐temperature and high‐pressure technology, and the density of surface‐modified diamond/Cu composites was less than 4 g cm−3. The W–WC–W2C@diamond/Cu composites have a thermal diffusivity as high as 331 mm2 s−1, and their thermal expansion coefficient is as low as 1.76 × 10−6 K−1. The interface coherent structure of the gradient layer‐coated diamond/copper composite can effectively improve the interface heat transport efficiency.

Sandwich-Structured Thermal Interface Materials with High Thermal Conductivity

“…Therefore, exploring thermal interface materials (TIMs) with high thermal conductivity has become crucial. − Ideal TIM materials require good mechanical properties to match the inherent surface roughness and maintain good contact of heater and heat sink during thermal cycling along with excellent heat transfer performance. − Polymer-based materials are widely used in TIMs due to their excellent mechanical properties and processability. However, their thermal conductivity is low and unstable at high temperatures, which has led to the development of alternative methods to enhance the performance of the high polymer matrix-based TIMs by adding high thermal conductivity materials, such as metal (Al, Ag, and Cu), ceramic (Al 2 O 3 , BN, and SiC , ), and carbon-based fillers (diamond, carbon fiber, − and graphene − ).…”

“…7−10 Polymer-based materials are widely used in TIMs due to their excellent mechanical properties and processability. However, their thermal conductivity is low and unstable at high temperatures, which has led to the development of alternative methods to enhance the performance of the high polymer matrix-based TIMs by adding high thermal conductivity materials, such as metal (Al, 11 Ag, 12 and Cu 13 ), ceramic (Al 2 O 3 , 14 BN, 15 and SiC 16,17 ), and carbon-based fillers (diamond, 18 carbon fiber, 19−22 and graphene 23−.25 ). Metal fillers have high thermal conductivity, but their corrosion resistance is weak, and their high density increases the burden of electronic components.…”

Revealing the atomic mechanism of diamond–iron interfacial reaction

“…Diamond, with excellent mechanical properties, ultrahigh hardness, high chemical inertness, low thermal expansion coefficient, and high thermal conductivity, [1][2][3] has been widely applied in various fields such as cutting tools, abrasive disks, polishing agents, high flux heat sink, highpower integrated circuit, semiconductor laser, and aerospace. [4][5][6][7][8][9][10] In practical applications, such as diamond tools, diamond drill bits, and high flux heat sinks, diamond will inevitably contact ferrous materials, and reactions happen at the interfaces; thus understanding the underlying mechanism is crucial to altering the interfacial binding, connections, and device performance. [11][12][13][14] Taking diamond and iron (Fe) interface as an example, it is reported that the interfacial reaction consists of two steps, that is, graphitization of diamond and subsequent diffusion of carbon atoms into Fe.…”