Meaning
Circuit board technology utilizes finer lines, smaller vias, and higher connection densities to accommodate complex integrated circuits. This high density interconnect approach allows for more components in a smaller footprint by using advanced fabrication techniques like laser drilling and sequential lamination. The design enables the integration of high pin count processors found in modern mobile and wearable devices.
Via Implementation
Microvias are the primary feature of these boards, typically measuring less than 150 microns in diameter. These tiny holes connect only a few layers of the board rather than passing through the entire stack. Blind and buried vias save surface area by staying within the inner layers.
Stacked via structures allow for direct vertical routing between multiple levels. Copper filling of the microvias provides a reliable electrical path and supports the subsequent lamination steps. This process requires specialized chemistry and plating equipment.
Precision laser systems are used to ablate the dielectric material without damaging the target copper pad.
Production Advantage
Reduced board sizes lead to lighter products and smaller enclosures. Shorter signal paths minimize parasitic capacitance and inductance, which improves performance for high speed signals. Signal integrity is easier to manage when the physical distance between components is minimized.
The use of thin materials also helps with thermal dissipation in tight spaces.
Space Constraint
Traditional manufacturing methods cannot achieve the pitch required for modern ball grid array components. High density boards solve this by allowing vias to be placed directly within the component pads. This technique eliminates the need for long breakout traces that consume valuable surface area.
Every square millimeter of the board is utilized for active circuitry.