The capability extract shows in thirty seconds what runs as standard and what carries a surcharge.
See capabilities →Send the files and an engineer reviews them against your build — free, before you enquire.
To the data check →A microvia is drilled with a laser rather than a bit, goes through exactly one dielectric layer, and is small enough to sit inside a BGA pad. It is the single feature that makes HDI possible — and stacking them is where most HDI cost and most HDI risk comes from.
The laser ablates resin and glass down to the copper of the next layer, which acts as a natural stop. Because the depth is fixed by the dielectric, the aspect ratio stays close to 1 : 1 regardless of how thick the board is — which is exactly why microvias plate reliably at diameters where a mechanical drill would never fill.
Connecting more than one layer means putting microvias on top of each other, and there are two ways to do it. Staggered offsets each level sideways, so every via plates onto a plain pad. Stacked places them directly in line, which requires each level below to be filled with copper and planarised before the next is drilled. Stacked buys routing density; it costs a plating step per level and it is markedly less forgiving.
At 100 µm the via sits in the pad itself. Below 0.4 mm pitch there is no other way to escape the array.
One dielectric layer deep means roughly 1 : 1 regardless of board thickness — plating reaches the bottom every time.
A microvia blocks only the two layers it joins, unlike a through-hole that blocks every layer it passes. That is where HDI density actually comes from.
| Parameter | Standard | Advanced | Note |
|---|---|---|---|
| Laser drill Ø | 0.100 mm | — | Verified minimum; top opening, the hole is slightly tapered |
| Dielectric depth | ≤ 0.100 mm | ≤ 0.075 mm | One layer only — never two |
| Aspect ratio | 0.8 : 1 | 1 : 1 | Depth : top diameter of the microvia — not the through-hole ratio of board thickness to drill |
| Capture pad | 0.30 mm | 0.25 mm | Pad the microvia is drilled into |
| Target pad | 0.30 mm | 0.25 mm | Landing pad on the layer below |
| Stacking levels | 2 | 3 – 4 | Each level needs fill and planarisation |
| Microvia pitch | ≥ 0.40 mm | ≥ 0.35 mm | Centre to centre |
| Copper in barrel | ≥ 12 µm | ≥ 15 µm | Lower than a through-hole; the depth is smaller |
Guide values for pre-selection. Binding values are confirmed per project against your data.
The points below are what most often comes back as a query after data review. Settling them before layout freeze saves a loop.
Staggered microvias plate onto plain pads and need no copper fill. Stacking is more expensive per level and considerably less tolerant. Stack only where the escape genuinely demands it.
A laser via must not span two dielectrics. If the connection needs to go deeper, it becomes two microvias with a pad between them, and that pad has to exist in the layout.
Every stacked level below the top must be copper-filled and planarised, or the next laser shot lands on a dimple and the plating pools.
A through-hole and a microvia landing on the same pad creates a plating and stress geometry that fails thermal cycling. Separate them.
Each level adds a lamination cycle, a laser drill cycle, a fill and planarisation step and a plating step. In practice a 1+N+1 and a 3+N+3 build differ by a factor, not by a percentage.
No. The laser stops on copper, and skipping a layer means ablating through copper — which it will not do cleanly. Two dielectrics means two vias.
A single staggered microvia is very reliable — its short barrel sees little z-axis strain. Stacked microvias concentrate strain at the interfaces and are the structure that IPC-6012 addenda specifically test for.
Design for 0.100 mm. It is the verified minimum laser diameter, runs as standard, plates comfortably and covers almost every BGA escape down to 0.4 mm pitch.
Send us your data or a rough sketch. We check feasibility, name the cost drivers and answer within one working day.