Ultrahigh Energy-Dissipation Thermal Interface Materials through Anneal-Induced Disentanglement

Thermal interface materials (TIMs) that function as reducing the contact thermal resistance between chip and cooling solution are indispensable in modern electronics. The development of electronics toward reduced feature size and being wearable has led to the need for new TIMs with both heat dissipation and high energy dissipation. However, the strong coupling between storage modulus and energy dissipation makes it difficult for TIMs to acquire these two properties simultaneously. Here, we propose an anneal-induced disentanglement strategy to obtain excellent heat dissipation properties of TIMs in a vibration environment, which is difficult for traditional TIMs. The dissociation of partially introduced dynamic covalent bonds in the polymer matrix releases the trapped entanglement and reduces storage modulus during the annealing process. Using prototypical dynamic thioester cross-linked polybutadiene adducted with maleic anhydride (PAMA), we achieved thioester-TIMs with tan δ higher than 0.94 in the frequency range of daily life, which is 4.7 times higher than that of traditional TIMs. In the actual application of 10 Hz vibration frequency, no temperature fluctuations (∼0 °C) are detected when using the thioester-TIMs chips, while the use of traditional TIMs show fluctuations of ∼3 °C. Such excellent performance creates new opportunities for TIMs design, and addresses current limitations in TIMs for flexible electronic packaging.