Sequential Lamination Overview

Sequential lamination is a cornerstone of advanced PCB manufacturing, especially for high-density interconnect (HDI) boards that need to pack a lot of electronics into a small space.


What Is Sequential Lamination?

Sequential lamination is a specialized technique used in the production of High-Density Interconnect (HDI) circuit boards. This method involves meticulously stacking layers of copper and insulating materials in a specific sequence. The goal is to construct multi-layer PCBs that are both compact and highly efficient.

Process Breakdown

Starting with the Foundation Layer:
  • Imagine a core structure or a sub-laminate (sub-lam).
  • Visualize a hole running through four individual copper layers, where each layer functions as an independent circuit.
Drilling and Plating:
  • Carefully drill precise holes through these layers.
  • These holes are then plated to establish electrical connections between the different layers.
Adding Copper Layers:
  • After the initial layers, additional copper layers are added.
  • Each new layer comes with its own set of connecting holes.
Layering and Laminating:
  • Every new layer is accompanied by the addition of dielectric material and a copper foil.
  • This is followed by a cycle of drilling and plating specific to that layer.
Repeating the Process:
  • The name “sequential lamination” comes from the repetitive nature of this process.
  • Repeat the above steps as needed, ensuring each new layer is integrated into the structure.


  • Length of time: The precision needed to align and bond each layer can extend the manufacturing process. It’s a trade-off for the superior outcome.
  • Cost: Given its complexity, the meticulous process could come with a higher price tag compared to other less complicated techniques.

Note: Sequential lamination is indispensable when it comes to routing fine-pitch, densely-packed designs. This technique often overlaps with via in-pad technology, streamlining the design flow in densely routed layouts.

Benefits of Sequential Lamination

  • More layers, more options: This approach enables the creation of PCBs with numerous layers, providing more avenues for detailed circuits and components.
  • Packed design: The dense assembly of components ensures the PCB is both compact and powerful.
  • Flexible design choices: Sequential lamination offers designers opportunities to innovate, enabling PCB customization to meet specific needs.

Stacked Vias Overview

Stacked vias are essential for modern PCB designs such as HDI boards. They ensure that the various PCB layers communicate effectively.

What Is a Stacked Via?

A stacked via consists of a series of connections within a PCB. These connections stack vertically, utilizing a specialized copper plating process.

Making a Stacked Via

Starting Point:
  • Begin at the central PCB layer, visualized by a through-hole, which serves as the primary base.
Layer Building:
  • Add each new layer with precision, similar to the sequential lamination process.
Incorporating Dielectric:
  • Introduce a dielectric with each new layer to ensure insulation between the active components.
Laser Precision:
  • Use lasers to form the necessary holes for the vias after adding the dielectric.
Copper Plating:
  • Plate the laser-formed holes with copper to establish the connections.


  • Intricate manufacturing process: Crafting stacked vias demands a higher degree of precision compared to their standard counterparts. Each via must be perfectly aligned to ensure optimal performance.
  • A matter of cost: The added intricacy in the design and production of stacked vias may be more expensive.

Note: The use of stacked vias, especially in high-density miniaturized designs, underlines the growing need for this technology in contemporary electronics. As devices become more compact and the demand for performance rises, tools like stacked vias become essential.

Benefits of Stacked Vias

  • Complex interconnections made simple: With stacked vias, designers have a tool that lets them weave intricate connections between the various layers of a PCB, ensuring every component communicates flawlessly with the others.
  • Miniaturization is the future: One of the challenges in electronics is making devices smaller without compromising their capabilities. Stacked vias are a big part of the solution, permitting PCBs to be more compact while still housing a dense network of circuits.

Similarities and Differences Between Sequential Lamination and Stacked Vias

Both sequential lamination and stacked vias are critical tools in PCB manufacturing, enabling the design of complex, multilayer boards. However, they serve distinct purposes based on the project’s demands.

Sequential lamination is ideal for detailed multilayer PCBs, especially HDI boards. It’s the go-to for high-speed or high-frequency designs where clear signal transmission is essential.

On the other hand, stacked vias are favored for compact designs, playing a vital role in miniaturization. They’re perfect for PCBs that need direct connections across several layers and those requiring better heat management.

In short, while both techniques are invaluable in PCB design, their application hinges on the unique needs of each project.

Applications for Sequential Lamination and Stacked Vias

  • Telecommunications infrastructure — Leveraging design flexibility from sequential lamination and space-saving from stacked vias for efficient telecom performance
  • Aerospace — Using sequential lamination to boost performance with stacked vias for essential multilayer connections, ensuring optimal flight electronic performance
  • Medical devices — Employing sequential lamination for intricate designs and stacked vias for device miniaturization, thus enhancing device efficiency and performance
  • Automotive electronics — Utilizing sequential lamination for high-performance pathways and stacked vias for effective signal management, ensuring safer and smarter vehicles
  • Consumer electronics — Benefiting from the design variety of sequential lamination and the compactness offered by stacked vias for modern gadgets
  • Computing and data storage — Adopting sequential lamination for efficient data pathways and stacked vias for greater interconnect capabilities
  • Energy systems — Driving greener energy solutions by harnessing sequential lamination for more reliable signals and stacked vias for improved signal and thermal efficiency

Sequential Lamination and Stacked Via Lead Times

Lead times are a vital factor to account for when considering the intricacies of PCB production, particularly for sequential lamination and stacked vias. Given the meticulous nature of these processes, each additional feature integrated within a PCB design necessitates an added lead time of approximately three days.

Cirexx’s Expertise in Sequential Lamination and Stacked Vias

Navigating the complexities of sequential lamination and stacked vias is no small task. That’s where Cirexx shines. Our expertise in these specialized areas ensures your PCB projects achieve unparalleled precision and performance. Whether you’re new to these techniques or seeking advanced consultation, our team is ready to assist. We’re committed to delivering tailored solutions that align seamlessly with your unique requirements.

Cirexx Is Your Sequential Lamination and Stacked Vias Manufacturer

Nestled in the heart of Silicon Valley, Cirexx stands tall with 43 years of specialization in PCBs, including sequential lamination and stacked vias. Our Santa Clara facility uniquely combines layout, fabrication, and assembly — a testament to our integrated approach. With a seasoned team boasting an average of 24 years in the field, we’re your reliable partner for precision, efficiency, and full-scale project integration.

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