半导体材料，不容忽视

Core Viewpoint - The semiconductor industry is undergoing a transformation towards 3D integration and larger substrates, fundamentally changing the role of materials in packaging. Materials that once served structural and electrical insulation purposes are now critical factors limiting device performance [1][15]. Group 1: Material Challenges - Modern packaging materials include a wide variety of polymers, adhesives, advanced dielectric materials, thermal interface materials, and composite laminates, which are more numerous than in previous generations [1]. - Many of these new materials lack sufficient long-term reliability data, leading to potential failure modes that may only become apparent after field cycling or PCB-level assembly [1][2]. - The transition to 3D architectures significantly expands the demand for advanced packaging materials, particularly for high-frequency AI applications that require specific dielectric constants and loss tangent values [1][2]. Group 2: Reliability Risks - Reliability risks often manifest after assembly, as polymers, adhesives, and bonding films continue to evolve, leading to issues such as loss of adhesion, relaxation after curing, swelling due to moisture absorption, and material migration within adhesive layers [2][5]. - The complexity of modern systems necessitates materials with precisely controlled dielectric properties, flow, and curing characteristics, as well as predictable thermomechanical stress behavior on large panels [2][5]. Group 3: Process Optimization - The industry is responding to these challenges through stricter process controls, system-level material specifications, and collaborative optimization strategies, treating films, interfaces, and deposition methods as unified reliability controls rather than independent variables [1][5]. - Early collaboration with stakeholders during material selection is crucial to ensure that materials possess the required chemical and physical properties [3][4]. Group 4: Mechanical Performance - As the number of materials increases, advanced packaging structures behave like composite materials, with each layer having distinct thermal expansion coefficients, viscoelastic responses, and curing characteristics [5][6]. - Mechanical stability is no longer a fixed attribute of layered structures but a dynamic target influenced by residual stresses generated during lamination and curing processes [5][6]. Group 5: Thermal Management - The rising power density in devices necessitates new thermal interface materials (TIMs) that can effectively manage heat dissipation while maintaining mechanical stability [9][10]. - The selection of TIMs is critical, as interface thermal resistance depends on wetting properties, void tendencies, and bonding layer thickness, which can significantly impact device reliability [9][11]. Group 6: Future Directions - The future of reliability in advanced packaging materials lies in viewing materials and processes as a unified system, with a focus on controlling variables at the nanoscale to enhance predictability and performance [12][15]. - The industry is encouraged to adopt a holistic approach to material selection, process conditions, and evolving stress fields to improve reliability and performance in larger panel sizes and higher stacking structures [15].