Title :
Thermal Conductivity Enhancement of Epoxy Composites by Interfacial Covalent Bonding for Underfill and Thermal Interfacial Materials in Cu/Low-K Application
Author :
Liang, Qizhen ; Moon, Kyoung-sik ; Jiang, Hongjin ; Wong, Ching Ping
Author_Institution :
Sch. of Mater. Sci. & Eng., Georgia Inst. of Technol., Atlanta, GA, USA
Abstract :
Nowadays with enhanced performance and reduced profile, electronics and photonics devices demand efficient heat dissipation and low operation temperature. Thereby, instead of traditional fillers (e.g., fused silica), thermally conductive silicon carbide (SiC) particles and multiwall carbon nanotubes (MWNTs) are applied here as fillers in composites for underfill and thermal interfacial materials (TIMs), respectively. SiC particles are coated with an ultrathin layer of silicon oxide by thermal oxidation at 800°C in air and consequently functionalized by γ-glycidoxypropyl-trimethoxysilane in order to graft epoxides on their surface. Moreover, MWNTs were chemically functionalized with carboxyls and hydroxyls in a concentrated acid mixture. Transmission electron microscopy, Fourier-transform infrared spectrascopy, and thermogravimetric analysis characterization indicates that both of the fillers are successfully functionalized, which makes their surface reactive with epoxy resin, resulting in interfacial covalent chemical bonding between the thermally conductive fillers and epoxy resin. It is found that interfacial chemical bonding across the interface between these functionalized fillers and polymer matrix can promote significant thermal conductivity enhancement of epoxy composites, which is promising for underfill and TIMs in Cu/low-K application.
Keywords :
Fourier transform spectra; bonds (chemical); carbon nanotubes; composite materials; cooling; infrared spectra; oxidation; polymer blends; resins; silicon compounds; thermal analysis; thermal conductivity; thermal management (packaging); transmission electron microscopy; γ-glycidoxypropyl-trimethoxysilane; Fourier-transform infrared spectroscopy; MWNT; TIM; carboxyls; concentrated acid mixture; electronics devices; epoxy composites; epoxy resin; functionalized fillers; fused silica; graft epoxides; heat dissipation; hydroxyls; interfacial chemical bonding; interfacial covalent bonding; interfacial covalent chemical bonding; multiwall carbon nanotubes; operation temperature; photonics devices; polymer matrix; silicon oxide; surface reactive; thermal conductivity enhancement; thermal interfacial materials; thermal oxidation; thermally conductive fillers; thermally conductive silicon carbide particles; thermogravimetric analysis characterization; transmission electron microscopy; ultrathin layer; underfill materials; Chemicals; Conductivity; Polymers; Silicon; Silicon carbide; Surface treatment; Thermal conductivity; Epoxy composite; interfacial covalent bonding; multiwalled carbon nanotube (MWNT); silicon carbide (SiC); thermal conductivity;
Journal_Title :
Components, Packaging and Manufacturing Technology, IEEE Transactions on
DOI :
10.1109/TCPMT.2012.2204885