Rethinking miniaturization: HDI PCBs as the key to next gen electronics
Everything is getting smaller in the electronics industry – except the requirements. Modern devices must provide a greater number of functions in a smaller space. HDI (High-Density Interconnect) circuit boards are a crucial factor in addressing this challenge. With them, it is possible to accommodate complex circuits in an extremely compact format without compromising performance or reliability. In this article, we consider the construction, advantages, and uses of HDI PCBs from a new perspective.
The new standard for high conductor rail density
High packing density and miniaturization capabilities are characteristics of HDI circuit boards. The following techniques are used for this purpose:
- Blind vias – microvia connection that link outer layers to inner layers
- Buried vias – hidden holes that serve exclusively to connect inner layers
- Ultra – fine widths and spacings of conductor paths
Thanks to these features, it is possible to efficiently connect even very complicated components such as Ball Grid Arrays (BGAs) or system-on-chip modules in a minimal space. Here, conventional printed circuit boards quickly reach their physical limits – HDI offers the solution.
High-density interconnect circuit boards from the inside
It is anything but trivial to build an HDI circuit board. Unlike standard PCBs, sequential lamination is often used for high-density interconnect boards. This means that the layers of the circuit board are built up and connected to each other one after the other, like a multi-story building with precisely planned connecting tunnels.
A key term in this context is "ELIC" – Every Layer Interconnect. This design integrates continuous microvia interconnects in all layers, enabling highly flexible connections. Even so-called Type III structures, based on IPC-2226 (Sectional Design Standard for High Density Interconnect Printed Boards), which combine multiple micro-via and buried-via layers, are widely used, especially in complex multi-layer designs with high pin density.
The three biggest advantages of HDI PCBs:
The actual advantages at a glance: the more compact design is one argument – but HDI PCBs convince with numerous other advantages. Not only are more compact designs made possible by the technology, but also electrical and thermal advantages that are difficult to achieve with conventional designs.
Signal quality
Shorter distances result in faster signals and fewer disruptions.
Thermal efficiency
Microvias can be used to distribute heat in a targeted manner.
Design freedom
Thanks to compact structures, it is possible to completely redesign products.
HDI technology: why higher PCB costs are worth it for modern electronics
Although HDI technology is advantageous, it also presents certain challenges. It brings new challenges, particularly in design and manufacturing. Laser drilling, multiple laminations, precise registration accuracy and microfine structures require specialized manufacturing processes.
The costs are also considerable: the production of HDI boards is more expensive than that of conventional multilayer PCBs – both in terms of the materials used and the manufacturing equipment and quality control required.
HDI-PCBs are not just an option – they are the answer to the pressure for innovation in compact high-performance systems.
Applications that require HDI
The use of HDI (high-density interconnect) technology is essential in many high-tech industries to realize modern, efficient, and compact electronic systems.
- Automotive and ADAS (Advanced Driver Assistance Systems) technologies: rapid data processing, minimizing potential disruptions.
- Medical technology: implants, diagnostic methods, wearable sensors.
- Aerospace: systems with critical space and weight requirements.
- Mobile devices and wearables: highly miniaturized and energy efficient.
HDI technology is often the engine of modern electronics. Without these circuit boards, autonomous vehicle systems, smartwatches, or portable diagnostic devices would be unthinkable. It enables powerful high-frequency electronics to be housed in the smallest of spaces – with high reliability and energy efficiency.
