Optimize the Interconnect:
Redefining Via Formation

By the time a via fails in the field, the root cause is already ancient history. It may have happened in a microsecond long laser pulse, a subtle beam deflection, or a surface condition that reflected energy instead of absorbing it.

In Episode 4 of On the Line with MKS, Casey Krueger, Director of Product Marketing for HDI via drilling at MKS, brings Optimize the Interconnect (OTI squarely into the factory—showing how via formation itself has become a system level engineering problem. This episode makes one thing clear: modern interconnect reliability begins before chemistry ever touches the panel.

Episode 4 of the OTI Story

Author: Ryan Wagner
Released: August 20, 2026

Via Formation Is No Longer Just “Drilling Holes”

For decades, laser drilling was judged primarily on accuracy and throughput. If the hole landed in the right place and met dimensional specs, the job was considered done.

OTI exposes why that mindset no longer works.

As Casey explains, the via is not just a geometric feature—it is a thermally and chemically prepared structure whose shape, taper, residue profile, and surface condition dictate everything that comes next. Laser drilling doesn’t merely remove material; it defines the environment that plating chemistry must survive and perform within.

That realization reshapes how via drilling systems are designed and evaluated.

A Third Degree of Freedom: AOD‑Based Beam Control

At the center of this shift is a technology many customers don’t initially realize they’re missing: acousto‑optic devices (AODs).

Traditional CO₂ laser drillers rely on two mechanisms to position a beam:

  • Stage motion
  • Galvanometer mirrors

AODs add a third, vastly faster degree of freedom—allowing beam steering and power modulation with no moving parts. The result is continuous motion without galvanometer settling delays, dramatically improving throughput and precision.

This isn’t a tuning tweak. It’s a fundamental change in how energy is delivered to the material.

Profiling the Pulse, Not Just the Spot

One of the most consequential ideas in Episode 4 is that laser pulses are no longer indivisible.

With AOD‑enabled hypersonic pulse control, a single laser pulse can be sliced into multiple segments—each with different timing, duration, and energy levels. This allows engineers to:

  • Apply high energy to penetrate copper
  • Immediately reduce power for polymer layers
  • Control taper and sidewall morphology precisely
  • Minimize thermal damage and residue

Via formation becomes a programmable process, not a fixed event.

And crucially, customers can control these profiles themselves—trained to adapt beam recipes to their own stackups and reliability goals.

Why Energy Efficiency Became a Differentiator

In modern factories, energy consumption is no longer a footnote—it’s a gating requirement.

Casey explains how OTI-driven beam control enables time multiplexing rather than traditional power multiplexing. Rather than splitting a pulse’s energy between two drilling heads (requiring much larger lasers), MKS systems redirect the pulse in time—delivering full energy sequentially to each head. The outcome is dramatic:

  • Roughly 50–60% lower energy consumption
  • Smaller lasers
  • Smaller chillers
  • Lower facility operating costs

This is process efficiency enabled by physics, not compromise.

Smaller, Faster, Lighter—and More Accurate

The implications extend beyond kilowatt‑hours.

Because AOD‑based systems don’t rely on massive granite bases to stabilize galvanometers, their physical footprint changes entirely. Casey highlights some underappreciated advantages:

  • 20–25% smaller system footprint
  • ~70% lower machine weight
  • Installation on upper factory floors
  • Easier shipping and deployment
  • Higher productivity per square meter

OTI turns via drilling from a space‑consuming bottleneck into a modular, flexible asset.

Where OTI Becomes Real for Customers

One of the most powerful moments in Episode 4 isn’t a data point—it’s an organizational change.

Casey describes MKS technology centers where drilling, wet processing, and plating are physically co‑located. Customers can now iterate full process loops—drill, clean, plate, inspect—in days instead of weeks.

This collapses learning cycles and allows OTI principles to be applied in real time, not theory.

Via formation stops being “upstream.” It becomes part of a continuous, collaborative system.

The Bridge Between Physics and Chemistry

Episode 4 is where the narrative arc pivots.

Microscopic insights from Episode 3 now connect directly to machine‑level behavior. Beam shaping determines surface smoothness. Pulse control influences crystallization outcomes. Energy delivery affects how chemistry performs downstream.

OTI, at this point, is no longer a philosophy—it is embodied in hardware, software, and factory layout.

And the story is still building.

The next chapter shifts focus again—this time to wet processes, where surface preparation, bond films, and transport dynamics turn laser precision into manufacturable reliability.

🎧 Listen for the Full Conversation

Next in the series: Where Wet Processes Decide What’s Possible (Episode 5)