HDI is the abbreviation of the high-density interconnector, it is a kind of technology to produce printed circuit boards. It is a circuit board with high distribution density using micro blind and buried hole technology.

According to the analysis of Zhanxin PCB Industry Research Institute, the market size of PCB in mainland China will increase from 27.1 billion US dollars in 2016 to 32.9 billion US dollars in 2018. 2017 and 2018 are the golden years of PCB development in China, with growth rates of 9.62% and 10.08% respectively.

HDI is the abbreviation for high-density interconnector. It refer to a technology for manufacturing printed circuit boards (PCB). Based on traditional multi-layer printed circuit board manufacturing technology, HDI introduces a new process of foil-RCC (Resin Coated Copper) laminate, supplemented by laser drilling, horizontal/vertical PTH (Plated through Hole) wet process and other processes produced by the blind hole/multi-layer buried PCB circuit boards.

printed circuit boards are one of the important electronic components in the electronic industry. Almost every electronic device, from electronic watches, calculators, computers, communication electronic devices, military weapon systems, as long as there are integrated circuits and other electronic components, in order to interconnect them, printed circuit boards are used.

In PCB design, wiring is an important step to complete product design. It can be said that the preparation work is done for it. In the whole PCB, the design process of wiring is the highest, the skills are the finest and the workload is the largest.

The layout should strive to meet the following requirements: keep the overall wiring as short as possible, with the shortest possible routing for critical signal lines; separate high-voltage, high-current signals from low-current, low-voltage weak signals; separate analog signals from digital signals; separate high-frequency signals from low-frequency signals; and ensure sufficient spacing between high-frequency components.

​When PCB makers make PCB files, we often need to add break-up tab on the unit board or panel. This paper describes the design specifications of common break-up tab.In the process of PCB design, for some reasons, the distance between the edge of components and the long edge of PCB is less than 5 mm. In order to ensure the efficiency and quality of PCB assembly, the designer should add the break-up tab to the corresponding long edge of PCB.

Because copper is easy to oxidize in air, the oxide layer of copper has a great influence on soldering. It is easy to form false welding and false welding. In serious cases, it will cause the pad and components cannot be welded. Therefore, PCB will have a process in manufacturing, coating (plating) on the pad surface to protect the pad from being oxidized.

Printed circuit boards, are providers of electrical connections for electronic components. PCB is used in almost all electronic devices, so it is called

Broad sense: printed circuit boards are equipped with resistors, capacitors, IC and other electronic components, and the products are electrically connected by soldering. Generally we also call it as PCBA.

PCB is made of many materials, such as glass fiberboard, paper substrate, metal substrate, plastic substrate, high frequency PTFE, etc.

In addition to considering the impedance of RF signal lines, the laminated structure of RF PCB also requires to consider heat dissipation, current, device, EMC, structure and skin effect. Usually we comply with the following basic principles in the layering and stacking of multilayer printed boards.