High-density interconnect is a rapidly evolving field, one that requires constant monitoring and education for those who want to stay abreast of the latest trends. HDI already extends well beyond microvias and fine lines, and it will become even more complex as semiconductor suppliers jam more transistors onto chips that have more pins spaced on finer pitches.

Signal integrity, power integrity, electromagnetic compliance, material choices, trace and space routing thicknesses, and embedded components are a few of the issues that must be considered when teams are developing designs that fall into the broad category of HDI.

"HDI today is an advanced design methodology that considers every possible state-of-the-industry electrical and manufacturing option before the project is released from planning to the actual engineers that will create and eventually assemble a finished product," said Daniel Smith, a 30-year veteran of software design firms and military contractors.

Developers entrusted with creating printed boards that house high-density ICs in compact systems must consider many different parameters.  

"You have a lot of degrees of freedom when it comes to density. Board size, pitch, the pin count of component packaging, and pins per square inch are some of the key elements that trigger this consideration," Smith said.

He will address these issues during Designers Day at the IPC APEX EXPO in Las Vegas on April 8. His presentation, "HDI - Educating Naysayers into Implementers" is one of five scheduled during the day-long Thursday session.

Staying abreast of change is important in all areas of electronics. But it's especially critical in the boards and circuits that link rapidly-advancing semiconductors to the systems that change almost daily as the developers of cell phones and other products add features and functions.

High-density designs are emerging as rapidly as the technology is changing. As geometries get smaller, the nuances that impact designs expand quickly.

"There are major challenges throughout the entire printed circuit board design process with respect to how to best embrace HDI methodology. I have a three year strategic roadmap of HDI opportunities to explore that has literally doubled in size in the past six months alone," Smith said.

He feels that constantly striving to learn more about HDI will be a key to ongoing success for both individuals and the companies they work for. He noted that there are many places to find good information. For example, Happy Holden's HDI Handbook and now Charles Pfeil's BGA Breakout and Routing books are available as Internet downloads.