High Density Interconnect PCB is used to meet the market needs of small and medium-sized complex designs in most market segments such as wireless, telecommunications, military, medical, semiconductor and instrumentation. The HDI board is one of the fastest growing technologies in the PCB. The HDI board contains blind vias and/or buried vias and typically contains microvias with a diameter of .006 or less. They have thinner lines and spaces that are always less than or equal to 3 mils and have a higher circuit density than conventional boards.
High Density Interconnects (HDI) board are defined as a board (PCB) with
a higher wiring density per unit area than
conventional printed circuit boards (PCB).
They have finer lines and spaces (<100 µm), smaller vias (<150 µm) and capture pads (<400 µm), I/O>300, and higher connection pad density (>20 pads/cm2) than employed in conventional PCB technology.
HDI board is used to reduce size and weight, as well as to enhance electrical performance.
The biggest difference between High Density Interconnect PCB and traditional circuit board is the three-dimensional circuit design of HDI, which replaces the via hole with micro holes (less than 6mil), blind holes and buried holes.
Buried hole plug purpose: resin filling of the buried hole after plating, to avoid bursting caused by insufficient PP flow glue filling during pressing.
The purpose of the blind hole plug hole: resin filling of the blind hole after plating, to avoid the copper plating at the copper plating blind hole can not be completely filled, resulting in the copper surface depression affecting the line production.