Precision for High-Density Interconnect
HDI
Enabling Complex Interconnects for High-Density Systems
Modern HDI technology extends beyond traditional PCB capabilities by leveraging laser microvias, sequential lamination, and ultra-fine-line processing with high-performance thin materials. The result is significantly increased interconnect density—allowing more functionality within a smaller footprint.
At the leading edge, advanced HDI platforms utilize multiple layers of copper-filled stacked microvias, enabling complex 3D interconnect structures that meet the routing and signal integrity demands of today’s high-speed, large pin-count, fine-pitch semiconductor devices. For applications requiring maximum performance within strict form factors, HDI delivers the density, reliability, and signal fidelity that advanced systems demand.
What is HDI PCB?
HDI PCB stands for High-Density Interconnect printed circuit board. As defined by IPC-2226, an HDI board is characterized by a wiring density per unit area that exceeds that of conventional PCBs. This higher density is achieved through the use of microvia technology — including blind vias, buried vias, and stacked or staggered microvias — enabling more interconnections within a smaller footprint. HDI PCBs are therefore also commonly referred to as blind and buried via boards or microvia boards.
Puruidy HDI PCB Capabilities
Definition: HDI PCBs utilize microvias, blind/buried vias, and build-up structures to achieve higher wiring density per unit area — ideal for space-constrained applications.
Key Applications: Smartphones, wearables, medical endoscopes, automotive ADAS modules, portable electronics.
| Feature | Capability |
| Via Types | Blind via, buried via, through-hole via, stacked via, staggered via |
| HDI Builds | 1+N+1, 2+N+2, 3+N+3, up to 6+N+6 (≥6 orders require evaluation) |
| Maximum Layers | Up to 60 layers (evaluation required above 30 layers) |
| Min. Trace / Spacing | 0.065mm / 0.065mm (65μm / 65μm) |
| Min. Laser Drilled Via | Standard 4 mil (100μm); 3 mil (75μm) requires evaluation |
| Min. Mechanical Drilling | 0.15mm |
| Aspect Ratio | Max 14:1 (evaluation required beyond) |
| PCB Thickness | 0.1mm – 8.0mm |
| Copper Weight (Finished) | 18μm – 70μm |
| Min. Solder Mask Bridge | 4 mil (green, ≤1OZ); 5 mil (other colors, ≤1OZ) |
| Max. Panel Size | Up to 21″ × 33″ (2–20 layers); length ≤ 1000mm |
High-Density Interconnect ("HDI") PCB
Stack-up structures
Common HDI PCB Stack-ups
Understanding the various stack-up configurations in HDI PCBs allows designers greater flexibility in layer assignment, component placement, and routing. This enables more efficient use of space and better optimization of the board layout. The common HDI PCB stack-up structures are illustrated in the diagram to the left.
Featured Product Solutions
After years of dedicated R&D and continuous technological advancement, Puruidy has established itself as a benchmark in the rapid manufacturing of small to medium-volume HDI PCBs. Evolving from early 1+N+1 and 2+N+2 stack-ups to today’s advanced 3+N+3, 5+N+5, 6+N+6, and 7+N+7 configurations, we have successfully transitioned from fast prototyping to reliable high-volume production. This journey reflects our commitment to stringent quality assurance and has shaped Puruidy into a trusted name in precision PCB manufacturing.
Automotive communication 2nd-order HDI board
3rd-order HDI board
3rd-order 5G IoT HDI PCB
6th-order arbitrary interconnection HDI buried/blind via circuit board
4-layer high TG thick copper immersion silver board
HDI second-order 6-layer laser drilling immersion gold
Application Scene
Our products are widely used in industrial control, communications electronics, medical, and consumer electronics. We take pride in our reputation as a partner to leading companies across these industries.
Industrial control
40%
Communication electronics
20%
Medical
10%
Consumer category
30%