Laminar Metal Foam: A Soft and Highly Thermally Conductive Thermal Interface Material with a Reliable Joint for Semiconductor Packaging

Abstract

Future electronic packaging technology requires semiconductor chips having a larger size and higher power for advanced applications, e.g., new energy conversion systems, electric vehicles, and data center servers, yet traditional thermal interface materials (TIMs) with a high thermal conductivity are generally stiff materials with weak joints, which cause the accumulated thermal stress to concentrate at the chip corners, leading to cracking and popcorn problems. To address such a critical challenge, herein for the first time we report a low-cost and high-performance porous copper (Cu)−indium (In) laminar structure as TIM, which can provide a superior thermal conductivity (50 W m −1 K −1 ) comparable to indium, yet the Young's modulus (1.0 GPa) is an order of magnitude lower than indium, which is a state-of-the-art value. Additionally, the In-based intermetallic compound (IMC) joints enable more robust mechanical interconnection above the melting point of pure indium, providing better high-temperature performance. The discontinuous IMCs spread the global interfacial thermal stress into numerous isolated local areas, ensuring a reliable joint to resist thermal−mechanical fatigue. In the silicon-TIM-copper package testing vehicles with a large die size (1 × 1 square inch), this structure shows excellent thermal management ability and superior reliability, compared with classical indium and classic commercial silver pastes.

Research Progress in Corrosion Protection Technology for Electronic Components

“…Semiconductor materials, as core materials for the manufacture of electronic components, play an important role in the design, manufacture, and packaging of electronic components [27,28]. Metals and their alloy materials, as the main materials used to make the internal fittings of electronic components, assume a key role in the miniaturization of chips through the continuous implementation of technologies such as small capacitance and high adhesion.…”

Enhancing Thermal Conductivity of Thermal Interface Materials through Aligned Liquid Metal Pillars: A Promising Strategy

“…This deficiency arises from the amplified interface thermal resistance caused by inadequate interface wettability and the inherent limitation of overall low thermal conductivity in these materials. 9−12 Liquid metal (LM) or low-melting point alloys have gained attention as high-performance thermal interface materials (TIM) due to their outstanding thermal conductivity and low toxicity, 13−20 which has been applied in various fields, such as electronics, 13 thermal management, 18 biomedical, 19 3D printing, 20 and so on. Among all kinds of LM, gallium-based liquid metal (GaLM) has been particularly studied for its potential in overcoming thermal barriers in computer chip cooling.…”

“…Liquid metal (LM) or low-melting point alloys have gained attention as high-performance thermal interface materials (TIM) due to their outstanding thermal conductivity and low toxicity, − which has been applied in various fields, such as electronics, thermal management, biomedical, 3D printing, and so on. Among all kinds of LM, gallium-based liquid metal (GaLM) has been particularly studied for its potential in overcoming thermal barriers in computer chip cooling. − However, direct application of LM faces challenges such as high cost, potential leakage, and difficulties in uniform application due to its high surface tension.…”