晶圆厂，根本性转变

Core Viewpoint - The semiconductor industry is experiencing a paradox where AI demand is rising and wafer investments are increasing, yet wafer shipments remain stagnant. This disconnect raises questions about the traditional supply-demand dynamics in the market [2][3]. Group 1: Market Dynamics - The current market dynamics cannot be solely explained by weak demand or delayed orders; instead, the demand pattern of fab operations has fundamentally changed [3]. - A key indicator, the wafer fab cycle time, has become a structural bottleneck, with a compound annual growth rate of 14.8% since 2020, indicating a fundamental slowdown in wafer fab capacity [4]. Group 2: HBM Market Insights - High Bandwidth Memory (HBM) is approaching a new inflection point, with HBM wafers requiring over three times the wafer area of standard DRAM, indicating significant potential wafer demand [6]. - HBM currently accounts for only 16% of total memory revenue, below the critical economic threshold of 25%, which is necessary for manufacturers to expand wafer investments [6]. Group 3: Quantitative Framework - A quantitative simulation framework models the interactions between four key variables: HBM penetration rate, DRAM bit rate growth, wafer fab utilization, and cycle time. Under current conditions, wafer input needs to increase by 23.9% annually to meet projected demand [8]. Group 4: Technical and Operational Challenges - The slow expansion of HBM is not solely due to investment timing; technical limitations such as low yields, customer certification delays, and process stability challenges are also critical factors [10]. - Additional delays are exacerbated by backend bottlenecks in CoWoS packaging, leading to inventory buildup of semi-finished wafers and limiting upstream wafer input [10]. Group 5: Strategic Implications - The analysis suggests three key actions for industry stakeholders: wafer suppliers should develop scenario-based capacity plans around the 25% HBM threshold; equipment manufacturers should anticipate demand driven by process transformations; and material suppliers should prepare for potential bottlenecks due to extended cycle times [14]. - The current stagnation should not be interpreted as a structural decline; rather, the market is in a strategic readiness phase, and once key conditions are met, wafer demand may respond non-linearly [14].