A Case Study in Conquering High Aspect Ratio Features

Estimated reading time: 1 minute

As demand for high-performance electronics is further driven by advances in AI and machine learning, the importance of high aspect ratio (HAR) through-holes in PCBs and IC substrates has become increasingly apparent. These vias play a vital role in enabling vertical interconnections in complex circuit architectures, especially within HDI structures, where maximizing space and enhancing electrical performance are crucial.

HAR through-holes help reduce signal path lengths and minimize parasitic inductance and capacitance. This is particularly essential for AI applications that demand high input/output (I/O) counts and low-latency communications across multilayer interconnects. Beyond their electrical advantages, HAR structures also contribute to mechanical integrity, providing stability during thermal cycling, which is an important factor as substrates become more layered.

The increasing complexity of heterogeneous integration, which involves closely stacking logic, memory, and AI-specific systems-on-chip (SoCs), further drives the need for reliable vertical interconnect solutions. Technologies like 2.5D and 3D IC packaging rely heavily on precise HAR via structures for efficient signal routing within compact designs.

To examine the fabrication capabilities for HAR through-holes, this article evaluates a modular vertical electrolytic copper plating system developed by GreenSource Engineering (GSE), which merges features of both horizontal and vertical plating lines, offering flexibility and optimal process control.

To continue reading this article, which appeared in the June 2026 I-Connect007 Magazine, click here.