High-Density Interconnect (HDI) printed circuit boards (PCBs) are increasingly popular in modern electronics due to their compact size, high functionality, and superior signal performance. HDI PCBs are known for their complex and intricate circuitry, which allows for more advanced electronic devices. One of the critical aspects of HDI PCB design is the choice of laminated structures. In this article, we will explore the commonly used laminated structures of HDI PCB boards and their significance in enhancing the overall performance and reliability of electronic devices.