HDI introduction

High-Density Interconnect (HDI) PCBs are advanced printed circuit boards characterized by a higher wiring density per unit area compared to standard PCBs.  

They incorporate:

• fine lines
• microvias,
• multiple layers

which allow for more compact and efficient designs.

• Blind / Buried Microvias: Small holes that connect different layers, enabling higher density and reducing the space needed for routing.

Key Features of HDI PCBs 01

• stable laser via formation
• controlled plating and copper filling
• copper balancing to avoid via fatigue under thermal cycling

• Smaller trace width and space: HDI PCBs can accommodate smaller components with tighter lead spacing, making them ideal for compact devices.

Key Features of HDI PCBs 02

• high-Tg FR-4 / FR-5

• polyimide for wide thermal cycling

• CTE-matched stackups to reduce warpage

• Layer Count: HDI boards often have multiple layers (4 to 20 or more), which support complex circuits and designs.

Key Features of HDI PCBs 03

• 2–6 oz copper options

• thermal-via grids
• heat-spreading planes for MOSFETs / IGBTs / SiC devices

Impedance Control: Enhanced design capabilities for controlled impedance, crucial for high-frequency applications.

Key Features of HDI PCBs 04

• bend-radius validation

• flex-tail stress analysis
• adhesive-less PI for long bending life

Applications of HDI PCBs

• Consumer Electronics: Smartphones, tablets, and wearables benefit from HDI's compactness and functionality.

  
  

• Telecommunications: Ideal for networking devices and communication systems.

• Medical Devices: Essential for compact, reliable medical equipment.

• Automotive: Used in advanced driver-assistance systems (ADAS) and infotainment.