Preparation of amino group functionalized diamond using photocatalyst and thermal conductivity of diamond/copper composite by electroplating

• Published in: Diamond and related materials Vol. 118; p. 108509
• Main Authors: Ishida, Naoya, Kato, Kazuki, Suzuki, Norihiro, Fujimoto, Kenjiro, Hagio, Takeshi, Ichino, Ryoichi, Kondo, Takeshi, Yuasa, Makoto, Uetsuka, Hiroshi, Fujishima, Akira, Terashima, Chiaki
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.10.2021; Elsevier BV
• Subjects: Amino-group functionalization; Bonding strength; Composite materials; Copper; Diamond; Diamonds; Electroplating; Heat conductivity; Heat sink; Heat transfer; Incompatibility; Interfacial bonding; Microdiamonds; Photocatalysis; Photocatalysts; Photocatalytic reaction; Plating; Plating baths; Thermal conductivity; Thermal resistance; Wettability; Wetting; Diamond; Amino-group functionalization; Copper; Photocatalytic reaction; Heat sink
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/j.diamond.2021.108509

We focused on a micro diamond (MD) particle with the highest thermal conductivity among existing materials and aimed to make a MD/copper composite material by electroplating. However, copper is naturally non-wetting with MD due to its chemical incompatibility, leading to weak interfacial bonding and high thermal resistance. We improved the wettability between MD and copper functionalized by the amino group on the MD using a photocatalytic reaction. The functionalization of the diamond surface by amino groups was achieved by treating the MDs in a 3-aminopropyltrimethoxysilane-containing solution. The amino group functionalized MD was dispersed in the electroplating bath, where copper was deposited on the MD. As a result, the composite material of amino group functionalized MD assisted by photocatalyst and copper improved their interfacial affinity and exhibited the high thermal conductivity of 595 W/m K. [Display omitted] •The amino group is successfully functionalized into diamond by photocatalytic assist.•The amino group on diamond improves wettability for Cu surface.•Diamond/Cu composite exhibits 595 W/m K with 20 vol% diamond.