Applications and Technical Considerations of HDI Boards in AI Devices

HDI (High-Density Interconnect) boards, a key advancement in PCB technology, play an increasingly critical role in AI devices. This article provides an in-depth analysis of HDI board applications and technical considerations in AI systems.

Core Advantages of HDI Boards

HDI boards use laser blind and buried via technology to achieve interconnects between any layers, offering the following advantages over traditional PCBs:

• Higher wiring density: supports finer line widths and spacings, down to 2.5mil.
• Smaller Aperture: Laser aperture as small as 0.075mm
• Thinner and lighter: Fewer layers and reduced board thickness for portable devices.
• Better electrical performance: Short, thin traces reduce signal transmission loss.

Application Requirements for AI Devices

AI devices such as AI servers, edge computing boxes, and smart cameras impose the following requirements on PCBA:

• High Density: AI chips feature numerous pins, requiring high-density routing.
• High Speed: High AI data transfer rates require low-loss materials.
• Thermal Management: High-power AI chips require effective cooling solutions.
• Stability: AI devices require high reliability for long-term operation.

Key Points of HDI Board Manufacturing Process

Producing high-quality HDI boards requires attention to the following process considerations:

• Laser Drilling: Control Hole Diameter, Shape, and Wall Quality
• Electroless Copper Plating: Ensures complete filling of blind and buried vias with no voids.
• Lamination Alignment: Multi-layer alignment accuracy controlled within ±25μm
• Impedance Control: Line width/spacing compensation, impedance deviation within ±5%

Future Trends

As AI technology continues to evolve, HDI boards will advance toward higher density, faster speeds, and improved thermal dissipation. Emerging technologies such as Any-layer HDI (Arbitrary Layer Interconnect) and SLP (Substrate-like PCB) will be increasingly adopted in AI devices, driving continuous performance enhancements in AI hardware.