Electronic design continues to improve the performance of the machine, while also trying to reduce its size. From mobile phones to smart weapons, small portable products, "small" is always the same pursuit. High-density integration (HDI) technology can make the end product design more compact, while meeting the electronic performance and efficiency of higher standards. HDI is widely used in mobile phones, digital cameras, MP3, MP4, notebook computers, automotive electronics and other digital products, among which the most widely used mobile phones. HDI board generally used to build-up (Build-up) manufacturing, the more the number of layers, the higher the technical grade plate. Ordinary HDI board is basically a laminated, high-level HDI with 2 or more layers of technology, while using stacked holes, electroplating fill, laser drilling and other advanced direct PCB technology. High-end HDI board is mainly used in 3G mobile phones, advanced digital cameras, IC board and so on.