Introduction:
HDI-HIGH DENSITY INTERCONNECT,HDI PCB Boards contain blind and/or buried vias and often contain microvias of .006 or less in diameter. They have a higher circuitry density than traditional circuit boards.

There are 6 different types of HDI PCB boards, through vias from surface to surface, with buried vias and through vias, two or more HDI layer with through vias,passive substrate with no electrical connection, coreless construction using layer pairs and alternate constructions of coreless constructions using layer pairs.

HDI any-layer printed circuit boards are the next technological enhancement of HDI microvia printed circuit boards: all the electrical connections between the individual layers consist of laser-drilled microvias. The main advantage of this technology is that all the layers can be freely interconnected. To produce these circuit boards, Xinchenger uses laser-drilled microvias electroplated with copper.

HDI PCB Structures:
1. 1+N+1 - PCBs contain 1 "build-up" of high-density interconnection layers.
2. i+N+i (i≥2) - PCBs contain 2 or more "build-up" of high density interconnection layers. Microvias on different layers can be staggered or stacked. 3. Copper filled stacked microvia structures are commonly seen in challenging designs.
4. Any Layer HDI - All the layers of a PCB are high density interconnection layers which allows the conductors on any layer of the PCB to be interconnected freely with copper filled stacked microvia structures ("any layer via"). This provides a reliable interconnect solution for highly complex large pin-count devices, such as CPU and GPU chips utilized on handheld and mobile devices.