With the continuous development of big data, the amount of data calculation has become larger, and the amount of data storage has also become larger, which has led to the birth of the storage product of big data server. These products are often large in size, and there will be a lot of hard disk interface protocol arrays such as SAS or SATA distributed on the board. In terms of PCB processing technology, materials of at least low loss level are used for processing. The thickness to diameter ratio is more than 10:1, and most of them will be distributed between 12:1 and 16:1, belonging to high thickness to diameter ratio products. The line grade is about 0.076/0.100mm. Some products will be processed by back drilling+resin plug hole to meet the insertion loss control requirements of high-speed signal. In addition, the use of high-speed materials leads to the removal of drilling contamination by plasma is also a standard process.