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The Future of PCB Microvia Drilling: 2026 Trends Shaping Next-Generation Electronics
Introduction
Behind every AI server, 1.6T optical module, and flagship smartphone lies a quiet manufacturing revolution: the relentless shrinking of printed circuit board (PCB) microvias. A decade ago, a 150 μm via was state-of-the-art. Today, high-end HDI and IC substrate makers routinely drill 50–75 μm blind vias, and R&D lines are pushing below 10 μm for next-generation heterogeneous integration. This article breaks down the defining trends of PCB microvia drilling in 2026.
Why Microvia Drilling Matters
The microvia — a tiny vertical conductive tunnel between HDI layers — directly determines three things:
- Signal integrity. Shorter, precise vies reduce stub length and insertion loss, which is mandatory for 1.6T and 3.2T optical engines.
- I/O density. Chiplets, HBM stacks, and AI accelerators demand thousands of vertical connections per mm². The only way to pack more I/O is to shrink the via and its pitch.
- Reliability. A microvia with heat damage or glass-fiber pull-out is a latent failure in thermal-cycling environments.
The Shrinking Via: From 150 μm to Sub-5 μm
| Application Segment | Target Diameter | Dominant Technology |
|---|---|---|
| Conventional multilayer PCB | 200–600 μm | Mechanical drilling |
| Standard HDI (L1/L2) | 100–150 μm | CO₂ laser |
| High-end HDI / mSAP | 50–75 μm | UV / Picosecond laser |
| ABF IC substrate | 20–30 μm | Picosecond UV laser |
| Next-gen packaging (pilot) | 3–5 μm | Picosecond UV + nano Cu barrier |
Mechanical drilling bottoms out around 150 μm. Below that, drill rigidity collapses and tooling cost spikes. Laser drilling — with no physical bit — is the only scalable path. Georgia Tech has already demonstrated fully opened 3 μm vias in 5 μm ABF film using picosecond UV on an 80 nm copper barrier, signaling where the industry is heading.
Technology Roadmap: Mechanical → CO₂ → UV → Ultrafast
Mechanical drilling handles most through-holes from 0.2–6.0 mm. It is low-cost and thermal-damage-free, but its minimum practical diameter is 150–200 μm, with positional accuracy of ±50–100 μm.
CO₂ lasers (9.3/10.6 μm) are the HDI workhorse — fast (up to ~1,000 vias/second) and cheap per hole, but they cannot directly ablate copper and produce a large heat-affected zone (50–100 μm).
UV nanosecond lasers (355 nm) are absorbed by both copper and dielectric, enabling direct copper opening without pre-treatment. They reach 25–75 μm vias with ±10–25 μm accuracy, but still leave a 10–20 μm HAZ.
Picosecond/femtosecond ultrafast lasers work by nonlinear multiphoton absorption, removing material before heat can diffuse — so-called "cold ablation." They deliver HAZ under 5 μm, minimum stable production vias of 30 μm, and no resin smear. The capital cost is higher, but they have already entered mass production at leading PCB makers for mSAP and 1.6T substrates.
Heat-Affected Zone (HAZ): The Hidden Quality Killer
HAZ — the ring of charred resin, fractured glass, and inner-layer copper erosion around a drilled hole — is what separates commodity drilling from premium drilling. A rough, carbonized via wall means weak electroless copper adhesion, plating defects, and eventual delamination under thermal cycling.
| Drilling Method | Typical HAZ |
|---|---|
| CO₂ laser | 50–100 μm |
| Nanosecond UV | 10–20 μm |
| Picosecond | < 5 μm |
| Femtosecond | < 2 μm |
For ABF substrates, M9 boards, and server-grade reliability, ultrafast laser is no longer a premium option — it is a process requirement.
Hybrid UV/CO₂ Systems: Best of Both Worlds
The fastest-growing platform architecture in 2026 integrates both sources on one gantry: the UV laser opens the copper aperture, while the CO₂ laser removes bulk dielectric. This cuts cycle time by roughly 30% versus pure UV, enables smaller vias than pure CO₂, and simplifies process flow — making it the default choice for high-mix HDI fabs.
New Materials, New Challenges
- M9-grade PCBs use high-purity quartz fiberglass (Mohs hardness >7 vs. 5–6 for E-glass). Mechanical drill life drops to ~1/5, and CO₂ causes resin carbonization and fiberglass tearing. Ultrafast lasers are currently the only production-proven solution.
- ABF substrates (CoWoS, CoPoS) are moving toward 20–30 μm vias on 5 μm films, with laser drilling extending into laser bump formation.
- Through-glass vias (TGV). TSMC has pilot lines for glass substrates with volume production within 2–3 years. Ultrafast lasers create TGV through nonlinear multiphoton modification — opening a brand-new equipment category.
Market Outlook
- China PCB laser drilling machine market: USD 832.65M in 2026 (+12.5% YoY).
- China UV laser drilling system market: RMB 2.11B in 2026 (+13.4%).
- Advanced packaging market: USD 60.7B (2025) → USD 91.1B (2030), ~8.5% CAGR (Yole).
Demand is pulled by AI servers, 1.6T optical modules, CoWoP architectures (targeting Rubin GPU in 2026, 30% high-end penetration by 2028), and the forced migration to mSAP as subtractive linewidths hit their 35 μm limit.
Practical Checklist for Equipment Buyers
- Match the laser to the material. FR-4 tolerates CO₂/UV; M9, ABF, and glass require ultrafast.
- Size the via, not the budget. A CO₂-only machine bought for a 50 μm roadmap will strand you in one product cycle.
- Calculate yield, not just capex. HAZ reduction often pays back in scrap savings within 18–24 months.
- Consider hybrid UV+CO₂ for mixed product lines.
- Ask vendors for M9/ABF process recipes that are customer-validated, not just datasheet specs.
Conclusion
PCB microvia drilling is entering its most consequential decade. The next chapter — sub-50 μm vias, cold ultrafast processing, quartz and glass substrates, and hybrid multi-source platforms — is being written right now in the fabs serving AI infrastructure. The microvia has always been small. Its strategic impact has never been bigger.
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What are the precautions for operating a laser marking machine?
1. It is strictly prohibited to start the laser power supply and Q-switching power supply when there is no water or the water circulation is abnormal.
2. The Q power supply is not allowed to operate without load (i.e., the output terminal of the Q power supply should be left floating).
3. In case of any abnormal phenomenon, first turn off the galvanometer switch and the key switch, and then conduct a check.
4. It is not allowed to start other components before the krypton lamp is lit to prevent high voltage from entering and damaging the components.
5. Pay attention to leaving the output terminal (anode) of the laser power supply suspended to prevent sparking and breakdown with other electrical appliances.
6. Keep the internal circulating water clean. Regularly clean the water tank and replace it with clean deionized water or pure water.
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What should we do when laser intensity decreases and the marking is not clear enough?
1. Turn off the machine and check if the laser resonant cavity has changed; Fine-tune the resonant cavity lens. Make the output light spot the best;
2. The acousto-optic crystal is offset or the output energy of the acousto-optic power supply is too low;
Adjust the position of the audio-visual crystal or increase the working current of the audio-visual power supply;
3. The laser entering the galvanometer deviates from the center: Adjust the laser;
4. If the current is adjusted to around 20A but the light sensitivity is still insufficient: the krypton lamp is aging. Replace it with a new one.
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How to maintain a UV laser cutting machine?
1. It is required to carry out regular cleaning every day, remove debris from the countertop, limiters and guide rails, and spray lubricating oil on the guide rails
2. The waste materials in the collection box should be cleared regularly to prevent excessive waste from blocking the exhaust port.
3. Clean the chiller once every 15 days, drain all the internal water, and then fill it with fresh pure water.
4. The reflector and focusing lens should be wiped with a special cleaning solution every 6 to 8 hours.
When wiping, use a cotton swab or cotton swab dipped in the cleaning solution to wipe from the center to the edge of the focusing lens in a counterclockwise direction.
At the same time, be careful not to scratch the lens.
5. The indoor environment can affect the lifespan of the machine, especially in damp and dusty conditions.
A damp environment is prone to causing rust on the reflective lenses and also easily leading to short circuits, discharge and sparking of the velvet laser.
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What accidents might be caused by the laser emission when using a laser cutting machine?
(1) A fire was caused by the laser coming into contact with flammable materials.
Everyone knows that the power of laser generators is very high, especially when it comes to high-power laser cutting machines, the temperature of the emitted laser is extremely high. The possibility of a fire being caused when a laser beam comes into contact with flammable objects is very high.
(2) Harmful gases may be produced when the machine is in operation.
For instance, when cutting with oxygen, it undergoes a chemical reaction with the cutting material, generating unknown chemical substances or fine particles and other impurities. After being absorbed by the human body, it may cause allergic reactions or discomfort in the lungs and other respiratory tracts. Protective measures should be taken when conducting work.
(3) Direct laser exposure to the human body can be harmful.
The damage caused by lasers to the human body mainly includes damage to the eyes and skin. Among the harms caused by lasers, the damage to the eyes is the most severe. Moreover, damage to the eyes is permanent. So when doing homework, you must pay attention to protecting your eyes.
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What is the focused spot diameter of nanosecond, picosecond and femtosecond laser?
Nanosecond: The light spot is 0.5-1mm.
Picosecond: The focused spot is around 0.02mm.
Femtosecond: Under the action of a laser beam with a high repetition rate of 100-200KHz and a very short pulse width of 10ps,
the focused spot diameter is as small as 0.003mm.
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What are the main applications of UV laser cutting machine?
The UV laser cutting machine can be used for cutting and depaneling PCB.
It can precisely cut and shape various types of PCB circuit boards with V-CUT and stamp holes, and open Windows and covers.
It can also be used for separating packaged circuit boards and ordinary smooth boards.
It is suitable for cutting various types of PCB substrates, such as ceramic substrates, rigid-flex boards, FR4, PCBs, FPCs, fingerprint recognition modules, cover films, composite materials, copper substrates, aluminum substrates, etc.
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Precautions for laser cutting machines to process various metal materials?
Copper and brass:
Both materials have high reflectivity and excellent thermal conductivity.
Brass with a thickness of less than 1mm can be processed by nitrogen laser cutting.
Copper with a thickness of less than 2mm can be cut. The gas used for laser cutting processing must be oxygen.
Copper and brass can only be cut when a "reflective absorption" device is installed on the system. Otherwise, reflection will damage the optical components.
Synthetic materials:
Processable synthetic materials include: thermoplastics, thermosetting materials and artificial rubber.
Aluminum:
Despite its high reflectivity and thermal conductivity, aluminum materials with a thickness of less than 6mm can be cut, depending on the type of alloy and the capacity of the laser.
When cutting with oxygen, the cutting surface is rough and hard.
When nitrogen is used, the cutting surface is smooth.
Pure aluminum is extremely difficult to cut due to its high purity.
Only when a "reflection and absorption" device is installed on the fiber laser cutting machine system can aluminum materials be cut.
Otherwise, reflection will damage the optical components
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What should be paid attention to when laser cutting stainless steel?
Laser cutting processing of stainless steel requires the use of oxygen, under the condition that edge oxidation is not a concern.
If nitrogen is used to achieve an edge free of oxidation and burrs, no further processing is required.
Coating an oil film on the surface of the sheet will achieve a better perforation effect without reducing the processing quality.