Core Viewpoint - Morgan Stanley believes that the transition from CoWoS to CoWoP faces significant technical challenges, and the reliance on ABF substrates is unlikely to change in the short term [1][2][8] Group 1: Technical Challenges - The CoWoP technology requires PCB line/space (L/S) to be reduced to below 10/10 microns, which is significantly more challenging than the current standards of ABF substrates [5][6] - The current high-density interconnect (HDI) PCB has an L/S of 40/50 microns, and even the PCB used in iPhone motherboards only reaches 20/35 microns, making the transition to CoWoP technically difficult [5][6] Group 2: Supply Chain Risks - Transitioning from CoWoS to CoWoP could introduce significant yield risks and necessitate a reconfiguration of the supply chain, which is not commercially logical given the timeline for mass production [8] - TSMC's CoWoS yield rate is nearly 100%, making a switch to a new technology unnecessarily risky [8] Group 3: Potential Advantages of CoWoP - Despite the short-term challenges, CoWoP technology has potential advantages, including shorter signal paths, improved thermal performance suitable for >1000W GPUs, better power integrity, and addressing organic substrate capacity bottlenecks [10] - The goals of adopting CoWoP include solving substrate warping issues, increasing NVLink coverage on PCBs without additional substrates, achieving higher thermal efficiency without packaging lids, and eliminating bottlenecks in certain packaging materials [10]