2oz 1.6mm Hdi Black PCB Board FR4 Quick PCB Prototype Immersion Au

HDI PCB Board PCB Hdi Black PCB Board PCB Board Assembly Low Volume PCB Low Volume PCB Manufacture Quick PCB Prototype​

4 Layer 1+N+1 HDI printed circuit board

High-density interconnect (HDI) PCBs are characterized by finer lines, closer spaces, and more dense wiring. They have a faster connection while reducing the size of a project. Normally, these boards also feature blind and buried vias, laser ablated microvias, sequential lamination, and via in-pads. A HDI board can house the functionality of the previous boards used. 

HDI Board Stack-up:

1+N+1 with laser microvia and mechanical buried core via. The “1” represents “build-up” or sequential lamination on each side of the core.
i+N+i (i>=2) PCBs contain 2 or more “build-up” of high-density interconnect layers. Microvias on different layers can be staggered or stacked. Copper filled stacked microvia structures are commonly seen in challenging designs.