This content originally appeared on DEV Community and was authored by Frank
Frank — Senior Electronics Engineer, USA
I’m Frank, a senior electronics engineer. Over the years I’ve designed everything from mixed-signal IC test boards to compact modules for wearable medical devices. One manufacturing step that keeps coming up as a game changer is laser drilling for PCBs.
In this piece I’ll explain how it works, why it matters for modern designs (from integrated circuits and microprocessors to tiny passive networks of resistors and capacitors), and what to look for when you need high-density, production-ready boards.
What is laser drilling?
Laser drilling uses a tightly focused beam of light to vaporize material and form tiny, precise holes, microvias in a PCB. Unlike mechanical drilling, there’s no physical bit touching the board. The laser’s energy melts or vaporizes copper and dielectric layers at the target location, producing clean holes with extremely small diameters and minimal mechanical stress.
How it works (brief, practical view)
Beam focus: The laser is focused to a pinpoint on the board where a via is required.
Material removal: High-energy pulses vaporize conductor or dielectric material, creating the via.
Cooling & inspection: The surrounding material cools quickly and the via is inspected for wall integrity and conductivity.
Why it matters for modern electronics
As ICs and microprocessor packages get denser and devices shrink, PCBs must support vertical routing and extremely fine interconnects. Laser-drilled microvias enable:
Miniaturization: Stack layers and route more signals in less area, critical for wearables, smartphones, and compact medical instruments.
Improved signal integrity: Clean vias and predictable geometry help with high-speed traces used by digital ICs and mixed-signal systems.
Support for advanced materials: Thin copper, flexible substrates, and specialized laminates (e.g., Rogers) are safer to process with lasers than mechanical bits.
Laser vs. mechanical drilling — practical differences
Precision: Lasers reach sub-0.1 mm features (microvias); mechanical drills are limited by physical bit size and runout.
Throughput: For dense, small vias, lasers can be far faster since no frequent bit changes or regrinds are needed.
Material stress: Mechanical drilling can induce cracks, delamination, or burrs, lasers avoid contact stress.
Cost profile: Higher upfront equipment cost for lasers, but lower tool-change and maintenance costs for high-volume or HDI work.
Benefits I care about as an engineer
Design freedom: I can place vias closer to pads and under BGA arrays without worrying about drill wander.
Repeatability: Production boards show consistent electrical performance, important when testing analog ICs and precision sensors.
Faster prototyping to production: Shorter turnaround when the board house supports laser microvias reliably.
Better yields on delicate materials: Especially helpful when a design uses thin copper, flexible substrates, or layered RF laminates.
Where you’ll see laser-drilled PCBs in the real world
Consumer electronics: Slim phones, tablets, and IoT devices where miniaturization is a must.
Automotive & EV electronics: Space-constrained modules with robust interconnects for sensors and control units.
Healthcare devices: Compact, high-reliability PCBs for monitors, pumps, and portable diagnostics.
Aerospace & defense: High-density, rugged boards for avionics and secure comms.
Practical tips when specifying laser-drilled PCBs
Ask for microvia diameter and tolerance (e.g., ±0.05 mm): This affects routing and pad design.
Specify barrel plating and wall integrity tests: For high-speed or high-reliability applications you want verified conductivity and adhesion.
Confirm material compatibility: Not every board house will guarantee the same results on Rogers, flex, or ultra-thin FR-4.
Request sample coupons: Inspect microvias under a microscope before committing a full production run.
When I need laser-drilled PCBs for prototypes or small production runs I go with services that explicitly list laser microvia capabilities and include test data.
For example, I’ve used JLCPCB on several prototype runs that required microvias and thin-stack HDI boards.
Laser drilling isn’t just a manufacturing buzzword, it’s a practical tool that opens design possibilities for integrated circuits, IC-heavy boards, and miniaturized systems.
Whether you’re routing signals for analog ICs, laying out mixed-signal boards, or packaging a new microprocessor-based module, understanding laser drilling will help you make better tradeoffs between manufacturability and performance.
Disclaimer: This educational article is not sponsored.
This content originally appeared on DEV Community and was authored by Frank