Improvement of thermal conductivity of underfill materials for electronic packaging

Effective heat dissipation is crucial to enhance the performance and reliability of the electronic devices. In this paper, the performance of encapsulants filled with carbon fiber was studied and compared with silica filled encapsulants. Encapsulants filled with a mixed combination of fillers for optimizing key properties were also investigated. The thermal conductance and electrical conductance were investigated, and glass transition temperature (Tg), thermal expansion coefficient (TCE), and storage modulus (E') of these materials were studied with thermal analysis methods. The carbon fiber and silica filled composites showed an increase of thermal conductivity three to four times that of silica filled encapsulants of the same filler loading, while maintaining or enhancing major mechanical and thermal properties, respectively.