What is HDI PCB?
HDI stands for High Density Interconnector. A circuit board which has a higher wiring density per unit area as opposed to conventional board is called as HDI PCB. HDI PCBs have finer spaces and lines, minor vias and capture pads and higher connection pad density. It is helpful in enhancing electrical performance and reduction in weight and size of the equipment. HDI PCB is the better option for high-layer count and costly laminated boards.
The emergence of HDI technology has propelled the development of the PCB industry by enabling the integration of denser components like BGAs and QFPs.
HDI PCB Applications
HDI PCBs are predominantly used in high-end electronic devices such as communication equipment, computers, medical devices, and automobiles. Their high density, reliability, and superior performance make them critical in these applications.
Consumer Electronics
Automotive Systems
Medical Devices
Stacked blind vias enable high-functionality circuits within small footprints, improving performance in signal acquisition, wireless telemetry, and imaging modules.
Industrial Automation
Telecommunications Equipment
Aerospace and Defense
Key HDI PCB Benefits
The evolution of high-density PCB technology has given engineers greater design freedom and flexibility than ever before. Designers using HDI high density interconnect methods now can place more components on both sides of the raw PCB if desired. In essence, an HDI PCB gives designers more space to work with, while allowing them to place smaller components even closer together. This means that a high-density interconnect PCB ultimately results in faster signal transmission along with enhanced signal quality.
HDI PCB is widely used to reduce the weight and overall dimensions of products, as well as to enhance the electrical performance of the device. The high-density PCB is regularly found in mobile phones, touch-screen devices, laptop computers, digital cameras and 4G network communications. The HDI PCB is also prominently featured in medical devices, as well as various electronic aircraft parts and components. The possibilities for high-density interconnect PCB technology seem almost limitless.
We’re capable of manufacturing HDI PCB up to 24 layers in various structures, check the following table for our available HDI PCB structures:
| HDI Structures |
Type of Micro vias |
Mass Production |
Small-Middle Batch |
Prototype | Available |
| 1+N+1 | Blind vias | Yes | Yes | Yes | 4 layers+ |
| 2+N+2 | Blind/Buried staggered vias |
Yes | Yes | Yes | 6 layers+ |
| 2+N+2 | Blind/Buried stacked vias |
Yes | Yes | Yes | 6 layers+ |
| 3+N+3 | Blind/Buried staggered vias |
/ | Yes | Yes | 8 layers+ |
| 3+N+3 | Blind/Buried stacked vias |
/ | / | Yes | 8 layers+ |
Check our HDI PCB capabilities by reviewing the table found below:
| Feature | Capability |
| Quality Grade | Standard IPC 2 |
| Number of Layers | 4 – 24layers |
| Order Quantity | 1pc – 10000+pcs |
| Build Time | 2days – 5weeks |
| Material | FR4 standard Tg 140°C,FR4 High Tg 170°C, FR4 and Rogers combined lamination |
| Board Size | Min 6*6mm | Max 457*610mm |
| Board Thickness | 0.4mm – 3.0mm |
| Copper Weight (Finished) | 0.5oz – 2.0oz |
| Min Tracing/Spacing | 2.5mil/2.5mil |
| Solder Mask Sides | As per the file |
| Solder Mask Color | Green, White, Blue, Black, Red, Yellow |
| Silkscreen Sides | As per the file |
| Silkscreen Color | White, Black, Yellow |
| Surface Finish | HASL – Hot Air Solder Leveling Lead Free HASL – RoHS ENIG – Electroless Nickle/Immersion Gold – RoHS Immersion Silver – RoHS Immersion Tin – RoHS OSP – Organic Solderability Preservatives – RoHS |
| Min Annular Ring | 4mil, 3mil – laser drill |
| Min Drilling Hole Diameter | 6mil, 4mil – laser drill |
| Max Exponents of Blind/Buried Vias | stacked vias for 3 layers interconnected, staggered vias for 4 layers interconnected |
| Other Techniques | Flex-rigid combination Via In Pad Buried Capacitor (only for Prototype PCB total area ≤1m²) |
HDI PCB vs. Standard PCB
| Aspect | Standard PCB | HDI PCB |
| Component Density | Typically <100 pins/in², limited by mechanical via size and trace spacing | ≥120 pins/in² supported through microvias, fine lines, and via-in-pad routing |
| Drilling Method | Mechanical drills only; min hole diameter ≈ 6 mil | Laser drilling for microvias down to 4 mil with tighter positional tolerances |
| Via Structures | Through-hole only, with long z-axis path | Blind vias, buried vias, stacked and filled microvias with controlled depth |
| Trace/Space Capability | Commonly 5 to 6 mil trace/space | 2.5 mil / 2.5 mil or finer with LDI registration accuracy to ±12 μm |
| Layer Count | 4 to 16 layers typically required for complex nets | Often 6 to 10 layers with optimized routing due to high interconnect density |
| Stackup Flexibility | Symmetrical cores with limited sequential build-up options | 1+n+1, 2+n+2, 3+n+3 with multi-cycle lamination process and custom dielectric setups |
| Routing Efficiency | Long signal paths and via stubs increase EMI and reduce bandwidth | Shorter routing with minimal via stubs improves signal integrity and reduces EMI |
| Impedance Control | Basic control using microstrip/stripline; wide tolerances (±10 to 15 Ω) | Modeled to ±5 Ω using hybrid PCB laminate sets and calibrated TDR measurements |
| Support for Fine Pitch | Not compatible with BGA pitches under 0.5 mm | Fully supports fine pitch (≤0.3 mm) CSPs and dense I/O arrays |
| Board Size and Thickness | Larger footprints and thicker profiles due to higher layers of a PCB | Reduced form factor with fewer layers and thinner dielectric stacks |
| EMI Performance | Susceptible to loop-area EMI from long traces and through-vias | Improved EMI control via short transitions and tightly stacked interconnect boards |
| Fabrication Cost | Lower for low-density applications with basic features | Higher per unit, but offset by reduced layer count, smaller board size, and routing gains |
| Application Suitability | General consumer, hobbyist, low-frequency circuits | Advanced PCB designs in telecom, automotive, aerospace, and portable electronics |
HDI PCB Manufacturer FAQs
What are the benefits of HDI PCBs?
HDI PCBs use laser-drilled microvias and fine-line routing to reduce signal delay, reflection, and crosstalk in high-speed interfaces like DDR and PCIe. Optimized layouts lower layer count by enabling direct interconnects between dense BGA pads and internal traces, reducing stub length and board thickness.
Resin-filled via-in-pad structures maintain pad flatness and solder joint reliability, while high-Tg materials and precise PCB design techniques support stable impedance and EMI control in telecom, medical, and automotive systems.
Is it possible to get stack-up drawings from you?
Yes, we provide standard stack-up diagrams or custom layer configurations based on your specific HDI PCB layout and impedance needs. Our engineering team will model copper distribution, dielectric spacing, and via structure placement before fabrication.
Do you offer any discounts?
We offer scaled pricing for HDI PCB manufacturing, including discounts for repeat orders, high-volume runs, and 4+ layer boards. Contact our team to get a quote tailored to your build and material selection.
Do you work with Gerber files only?
We primarily use Gerber RS-274X, but we also support ODB++, IPC-2581, and other standard design data formats. IPC-2581 improves CAD-to-CAM translation, reducing manufacturing errors and speeding up pre-production review.
What design considerations are important for HDI PCBs?
Important considerations include via structure selection (staggered vs. stacked), PCB stackup balance, controlled impedance modeling, and copper-to-dielectric ratio. Designers must consider prepreg flow, resin fill compatibility, trace spacing for EMI control, and laminate Tg to meet thermal limits.