Free Trials

Download a free trial to find out which Altium software best suits your needs

How to Buy

Contact your local sales office to get started on improving your design environment


Download the latest in PCB design and EDA software

  • Altium Designer

    Complete Environment for Schematic + Layout

  • CircuitStudio

    Entry Level, Professional PCB Design Tool

  • CircuitMaker

    Community Based PCB Design Tool


    Agile PCB Design For Teams

  • Altium 365

    Connecting PCB Design to the Manufacturing Floor

  • Altium Concord Pro

    Complete Solution for Library Management

  • Octopart

    Extensive, Easy-to-Use Component Database

  • PDN Analyzer

    Natural and Effortless Power Distribution Network Analysis

  • See All Extensions

    World-Renowned Technology for Embedded Systems Development

  • Live Courses

    Learn best practices with instructional training available worldwide

  • On-Demand Courses

    Gain comprehensive knowledge without leaving your home or office

  • Altium 365 Viewer

    View & Share electronic designs in your browser

  • Altium Designer 20

    The most powerful, modern and easy-to-use PCB design tool for professional use


    Annual PCB Design Summit

    • Forum

      Where Altium users and enthusiasts can interact with each other

    • Blog

      Our blog about things that interest us and hopefully you too

    • Ideas

      Submit ideas and vote for new features you want in Altium tools

    • Bug Crunch

      Help make the software better by submitting bugs and voting on what's important

    • Wall

      A stream of events on AltiumLive you follow by participating in or subscribing to

    • Beta Program

      Information about participating in our Beta program and getting early access to Altium tools

    All Resources

    Explore the latest content from blog posts to social media and technical white papers gathered together for your convenience


    Take a look at what download options are available to best suit your needs

    How to Buy

    Contact your local sales office to get started improving your design environment

    • Documentation

      The documentation area is where you can find extensive, versioned information about our software online, for free.

    • Training & Events

      View the schedule and register for training events all around the world and online

    • Design Content

      Browse our vast library of free design content including components, templates and reference designs

    • Webinars

      Attend a live webinar online or get instant access to our on demand series of webinars

    • Support

      Get your questions answered with our variety of direct support and self-service options

    • Technical Papers

      Stay up to date with the latest technology and industry trends with our complete collection of technical white papers.

    • Video Library

      Quick and to-the-point video tutorials to get you started with Altium Designer

    Microvia Technology and Beyond for HDI Design

    Zachariah Peterson
    |  May 27, 2019

    Microvias and HDI traces on a green PCb

    HDI routing made possible with microvia technology

    If you have ever opened up the case on a broken smartwatch or smartphone, then you know the amount of functionality that is packed into such a small device. Enter microvia technology. Shrinking via structures have facilitated high density interconnect layout and routing in PCBs, allowing ever more functionality to be packed into small footprints.

    As consumers continue to demand more functionality on individual devices, with further scaling hindered by quantum tunneling, PCB designers have a role to play in decreasing device form factors and packing more functionality into a single package. What new multilayer routing architectures will arise from these efforts?

    From Through-Hole to ELIC

    When working with a small number of layers and a relatively thin board, you can usually get away with through-hole vias. At some point, you’ll be routing so many connections over a small area that you will need unique ways to reach the inner layers of your board while still conserving valuable board space. Through-hole vias don’t allow multiple signals to be routed through a given interior layer area. As the number of layers in your board increases, through-hole vias will still only allow you to route signals between two layers.

    Even if through-hole via size approaches microvia sizes, it will still not solve the problem of taking up unnecessary interior board space. Buried vias help the situation somewhat, although they still take up a decent amount of board space if you have to route between layers that are not adjacent. This is where microvias give you significantly more flexibility.

    Microvias were originally used to route signals between adjacent board layers when the via holes were too small to place with a drill bit. Instead, a laser places these vias in a single layer of a PCB, while the board is created using sequential buildup (SBU). Note that we also use SBU to place traditionally drilled blind and buried vias in a layer stack, but microvias are simply  laser-placed and plated using a tailored electrolytic deposition process.

    Just like drilled vias, microvias come in the blind and buried variety, but they only span a single layer. If you need to span across multiple layers, you can use stacked microvias or skip vias to route the desired connections. Some manufacturers estimate that using microvias for HDI reduces the total board space occupied by vias by 60% to 70%. This leaves more room for routing signal in the interior of your board. Creative use of microvias also allows you to reduce layer counts.

    Integrated circuits on a green PCB

    Microvias used for BGA escape routing

    Microvias are really a necessity when placing components with high pin densities. As pin densities continually increase, we need to place more microvias directly onto mounting pads. We also fill and plate these laser-drilled microvias to prevent solder from wicking into the via and forming a weak electrical connection.

    Beyond Microvia Technology: Next Generation HDI Routing

    One recent innovation in this area is the development of every-layer interconnect (ELIC) routing. GPUs, CPUs, memories, and other BGA-mounted devices with extremely fine pitch routinely use ELIC. This via architecture facilitates connections throughout the interior of a board without the need for a core in the center of the board. This architecture essentially uses stacked, copper-filled microvias to connect the layers of the board.

    Increasing routing and layout density even further will require new architectures for routing between layers in a multilayer PCB. The most promising innovation for this is vertical conductive structures, or VeCS. This unique multilayer PCB architecture allows for a larger number of tracks between BGA pads compared to dog bone fanouts or via-in-pad. For a given board and component arrangement, this type of routing architecture can decrease dependence on multiple interior signal layers for HDI routing.

    The VeCS architecture is not cylindrical. Instead, a copper-plated groove routes into the board surface. A slightly wider drill punches holes along the groove, leaving behind straight vertical conductors that pass through the inner layers. VeCS doesn’t require any other specialized manufacturing techniques or tooling, and it can provide the same functionality as ELIC.

    HDI routing for a CPU with microvia technology

    Keeping up with microvia technology and newer innovations in HDI routing takes design software with a full suite of mechanical and electrical design tools in a single package. Altium Designer is the only PCB design software platform that contains the best schematic design, routing and layout, signal analysis, and deliverable generation tools in a single interface. You can generate the deliverables your manufacturer needs to fabricate new routing architectures for HDI PCBs.

    Download a free trial of Altium Designer today to learn more about the industry’s best design, simulation, and verification features. Talk to an Altium expert today to learn more.

    About Author

    About Author

    Zachariah Peterson has an extensive technical background in academia and industry. Prior to working in the PCB industry, he taught at Portland State University. He conducted his Physics M.S. research on chemisorptive gas sensors and his Applied Physics Ph.D. research on random laser theory and stability.His background in scientific research spans topics in nanoparticle lasers, electronic and optoelectronic semiconductor devices, environmental systems, and financial analytics. His work has been published in several peer-reviewed journals and conference proceedings, and he has written hundreds of technical blogs on PCB design for a number of companies. Zachariah works with other companies in the PCB industry providing design and research services. He is a member of IEEE Photonics Society and the American Physical Society.

    most recent articles

    Back to Home