Background Theory > PCB Design > High Density Interconnect (HDI) PCBs

High Density Interconnect (HDI) PCBs refer to a type of printed circuit board that is designed with a higher density of components and traces than traditional PCBs. HDI PCBs are widely used in modern electronics to accommodate smaller and more complex designs, particularly in devices like smart-phones, tablets, laptops, and other compact electronic products. The primary goal of HDI PCBs is to increase the efficiency of the electronic circuits while reducing the overall size and weight of the device.

Key features and advantages of HDI PCBs include:

•Increased Density: HDI PCBs have a higher density of components and interconnections, achieved through the use of advanced manufacturing techniques such as microvias, blind vias, and buried vias. This allows for more components to be placed on a smaller board.

•Reduced Size and Weight: The smaller size of HDI PCBs allows for more compact electronic devices. This is particularly important in applications where space is limited, such as wearable devices and portable electronics.

•Improved Electrical Performance: The reduced trace lengths and improved signal integrity offered by HDI PCBs can lead to better electrical performance and reduced signal loss, making them suitable for high-speed and high-frequency applications.

•Enhanced Reliability: HDI PCBs often feature smaller vias, which can reduce the risk of via failure. The buried and blind vias also allow for more efficient routing, reducing the chances of signal interference.

•Multilayer Design: HDI PCBs typically have multiple layers, which allow for complex routing and better separation of different signal types, helping to reduce electromagnetic interference (EMI).

•Cost Efficiency: While HDI PCBs can be more expensive to manufacture compared to traditional PCBs, they often lead to cost savings in the overall product design by enabling smaller and more efficient designs.

•Flexibility in Design: HDI technology allows for more flexible and creative PCB design layouts, which can be critical in the miniaturization of advanced electronic devices.

HDI PCBs come in various types, including:

•1+N+1 HDI: This type has a single build-up layer on either side of a core layer. It is commonly used for applications requiring relatively fewer components. see: 1+N+1 HDI

•2+N+2 HDI: This type features two build-up layers on either side of a core layer. It provides higher density and is suitable for more complex designs. See: 2+N+2 HDI

•Any-layer HDI: This type allows vias to be placed in any layer, providing the highest density and flexibility in design. It is commonly used in advanced applications such as smart-phones. see: Any-layer HDI

In summary, HDI PCBs are a crucial technology for achieving compact and high-performance electronic devices, particularly in the context of our increasingly connected and miniaturized world.

Also see: Microvias