玻璃基板，一步之遥

Core Viewpoint - Glass substrates are emerging as a superior alternative to organic substrates in advanced packaging due to their flatness, lower thermal expansion coefficient, and reduced warpage issues, making them ideal for high-frequency applications and 6G communications [2][3][5]. Group 1: Advantages of Glass Substrates - Glass substrates provide significant improvements in warpage reduction (50%) and positioning accuracy (35%) compared to organic substrates, facilitating the implementation of redistribution layers (RDL) with line widths and spacings below 2 micrometers [2]. - The dielectric constant of glass (2.8) is much lower than that of silicon (12), resulting in significantly lower transmission losses and enhanced signal integrity for high-frequency applications [3]. - Glass substrates are versatile and can be used as carriers, core substrates for embedded components, 3D stacking materials, or sealed cavities for sensors and MEMS [2]. Group 2: Manufacturing Challenges - Glass cutting is prone to micro-cracking, and the challenge of repeatedly manufacturing thousands of fine-pitch through-glass vias (TGV) hinders the full potential of glass substrates [3][22]. - The laser-induced deep etching (LIDE) technology is being improved to facilitate mass production of TGVs, allowing for the etching of vias as small as 3 micrometers with a spacing of 5 micrometers [10][11]. Group 3: Applications in 6G Technology - Glass substrates are ideal for 6G wireless communication networks, which require data rates exceeding 100 GHz, due to their high-frequency transmission capabilities and low loss characteristics [5]. - Heterogeneous integration in stacked glass can combine high-frequency front-end chips with low-loss interconnects, enhancing the performance of large-scale antenna arrays [5]. Group 4: Innovations in Glass Processing - The use of ABF (Ajinomoto Build-up Film) as a low-k dielectric and adhesive for glass bonding has shown promising results, achieving electrical performance up to 220 GHz with minimal loss [5][8]. - New methods for cutting glass substrates, such as embedding cut substrates in organic resin for edge protection, are being explored to minimize damage during handling [24]. Group 5: Yield Improvement Techniques - Predictive modeling and machine learning are being utilized to enhance yield rates in glass substrate manufacturing, particularly in identifying and mitigating defects early in the production process [18][19]. - The development of automated systems for wet etching and drying processes is aimed at improving the efficiency and yield of TGV manufacturing [10][11]. Group 6: Future Directions - The glass ecosystem is preparing for the continued growth in chip and substrate sizes in multi-chip advanced packaging, with significant progress being made in laser modification and high-frequency etching techniques [28]. - Ongoing research aims to further reduce micro-cracking during cutting processes and improve the compatibility of new processing techniques with stringent design rules [29].