Advances on Thermally Conductive Epoxy‐Based Composites as Electronic Packaging Underfill Materials—A Review

Abstract

The integrated circuits industry has been continuously producing microelectronic components with ever higher integration level, packaging density, and power density, which demand more stringent requirements for heat dissipation. Electronic packaging materials are used to pack these microelectronic components together, help to dissipate heat, redistribute stresses, and protect the whole system from the environment. They serve an important role in ensuring the performance and reliability of the electronic devices. Among various packaging materials, epoxy‐based underfills are often employed in flip‐chip packaging. However, widely used capillary underfill materials suffer from their low thermal conductivity, unable to meet the growing heat dissipation required of next‐generation IC chips with much higher power density. Many strategies have been proposed to improve the thermal conductivity of epoxy, but its application as underfill materials with complex performance requirements is still difficult. In fact, optimizing the combined thermal–electrical–mechanical–processing properties of underfill materials for flip‐chip packaging remains a great challenge. Herein, state‐of‐the‐art advances that have been made to satisfy the key requirements of capillary underfill materials are reviewed. Based on these studies, the perspectives for designing high‐performance underfill materials with novel microstructures in electronic packaging for high‐power density electronic devices are provided.

One-Pot Synthesis of Hyperbranched Polymers via Visible Light Regulated Switchable Catalysis

“…Epoxy resins (EPs) are emerging as the most widely used thermosetting materials in semiconductor packaging materials, electrical insulation substances, and high-performance composites. 58 Yet, compared with conventional thermosetting resins, they suffer from a reduction in volume shrinkage during the curing process and display poor resistance for crack initiation/propagation. Toward this end, hyperbranched epoxy compounds are among the most desirable modi ers as they can effectively toughen epoxy thermosets without sacri cing their processability.…”

Progress in the design and synthesis of biobased epoxy covalent adaptable networks

“…3 They are widely used as coatings, adhesives, electronic packaging materials, and composites in various materials such as household products, aerospace materials, automobiles, architecture, and electrical devices. 4–10 However, permanently cross-linked epoxy resins are difficult to heal or repair when damaged (such as cracks, fractures, and punctures) under high stress or pressure, thus shortening the life cycle of the materials they are used in. Even worse, they cannot be reprocessed or remolded, making it challenging to recycle or reuse the ever-increasing epoxy waste.…”

Enhanced Thermal Conductivity of Epoxy Composites by Introducing 1D AlN Whiskers and Constructing Directionally Aligned 3D AlN Filler Skeletons

“…If metal particles and carbon materials are used as fillers of TIMs, significant leakage current losses and arcing faults have a high probability of occurring due to their high electronic conductivity. Therefore, the ideal high-performance filling material for electronic packaging needs to have high thermal conductivity, high resistivity, excellent flame retardancy, low dielectric constant, and so forth. − As a result, inorganic ceramic materials such as oxides and nitrides are receiving more and more attention.…”