Core Viewpoint - The article discusses the significant transformation in data centers from a "compute-centric" approach to a "bandwidth-driven" model, highlighting the rise of High Bandwidth Memory (HBM) as a crucial infrastructure for large model computations [1][2]. Group 1: HBM Market Dynamics - HBM has evolved from being a standard component in high-performance AI chips to a strategic focal point in the semiconductor industry, with major players like Samsung, SK Hynix, and Micron viewing it as a key driver for future revenue growth [2][4]. - SK Hynix has established a dominant position in the HBM market, holding approximately 50% market share, with a staggering 70% share in the latest HBM3E products [6][10]. - Samsung is also actively pursuing custom HBM supply agreements with various clients, indicating a competitive landscape among these semiconductor giants [6][10]. Group 2: Customization Trends - Customization of HBM is becoming a necessity, driven by cloud giants seeking tailored AI chips, with SK Hynix already engaging with major clients like NVIDIA and Microsoft for custom HBM solutions [4][5]. - The integration of base die functions into logic chips allows for greater flexibility and control over HBM core chip stacks, optimizing performance, power consumption, and area [7][9]. Group 3: Hybrid Bonding Technology - Hybrid bonding is emerging as a critical technology for future HBM development, addressing challenges posed by traditional soldering techniques as stacking layers increase [12][18]. - Major companies, including Samsung and SK Hynix, are exploring hybrid bonding for their next-generation HBM products, which could lead to significant advancements in performance and efficiency [13][18]. Group 4: Future HBM Innovations - The article outlines the anticipated evolution of HBM technology from HBM4 to HBM8, detailing improvements in bandwidth, capacity, and power efficiency, with HBM8 expected to achieve a bandwidth of 64 TB/s and a capacity of up to 240 GB per module [20][21][27]. - Key innovations include the introduction of 3D integration technologies, advanced cooling methods, and AI-driven design optimizations, which are set to enhance the overall performance and efficiency of HBM systems [29][30]. Group 5: Competitive Landscape - The competition among DRAM manufacturers and bonding equipment suppliers is intensifying, with companies needing to collaborate across various domains to succeed in the evolving HBM market [33]. - The future of HBM technology will likely be shaped by the ability of companies to integrate diverse processes and resources, with the race for dominance in the post-AI era just beginning [33].

Core Viewpoint - The article discusses the limitations and challenges of interposer line lengths in advanced packaging, highlighting the differences between electrical and optical interposers and the implications for signal integrity and transmission efficiency [1][11]. Group 1: Interposer Types and Challenges - There are two main types of interposers in production: organic interposers (RDL) and silicon interposers, with organic interposers being significantly cheaper to produce but having larger feature sizes [2]. - The use of silicon does not necessitate narrow lines, as wider signal lines require more signal layers, which is undesirable for manufacturers [2][3]. - The resistance of narrow lines in organic interposers leads to significant insertion loss, which is a major concern for clients [3][5]. Group 2: Signal Integrity and Grounding - Signal integrity is heavily reliant on good grounding, typically provided by ground layers, which can serve multiple functions including power delivery and impedance control [7]. - Controlled impedance is crucial for maintaining signal quality, and even short lines can suffer from interference or crosstalk [7][8]. - Designers strive to minimize loss and maintain grounding around high-speed lines, which can be challenging due to manufacturing constraints [8][10]. Group 3: Optical Interposers and Future Directions - Optical interposers face fewer limitations compared to electrical ones, as optical signals can transmit over longer distances [1][11]. - The integration of optical devices into packaging is a growing trend, with technologies like Lightmatter's Passage aiming to combine CMOS and silicon photonics within an interposer [11][12]. - While photonics offers a potential long-term solution to line length limitations, it is not yet ready for mass production [14].