HDI PCB is the shortened form of High Density Interconnector PCB. It's a technology of printed circuit board production.

This is a circuit board that uses micro-blind buried hole technology, with very high line density and complexity, and can achieve high-speed signal transmission and reliability design. The main features of HDI circuit boards are multi-layer lines, thin plates, small apertures, dense wiring and fine lines, and are widely used in mobile phones, computers, network communications, automotive electronics and other fields.

The manufacture of HDI circuit boards is one of the fastest-growing areas in the printed circuit board industry. It is a compact product designed for small-capacity users. As electronic products develop towards high density and high precision, HDI circuit boards have put forward the same requirements accordingly. The production of HDI boards uses advanced fine line production technology, so that the line width and spacing reach the micron level. This high-precision line layout not only improves the performance of the circuit board, but also reduces energy consumption and electromagnetic interference. Therefore, HDI circuit boards are widely used in high-end electronic devices such as smartphones, tablets, and laptops.

In the manufacturing process of HDI circuit boards, the process of drilling and metallization in the holes is used to achieve the connection function between the lines of each layer. Compared with traditional multi-layer circuit boards, HDI circuit boards adopt the build-up method, use blind and buried vias to reduce the number of through holes, save the PCB wiring area, and thus greatly increase the density of components. Therefore, they have quickly replaced the original multi-layer boards in the use of smart phones. With the continuous advancement of electronic technology, electronic products continue to develop in the direction of light, thin, short and small, and high-density interconnect (HDI) technology has come into being. ‌