What this section is for
Fabrication is the part of a PCB order where the buyer has the least visibility and the most exposure. By the time a defect is detectable at incoming inspection, the panels are already cut, the money is already committed, and the schedule has already been consumed.
This section explains the sequence in enough detail that a buyer can tell where a problem could have been caught, and a designer can tell which of their decisions created the risk. It is written from the process side, which means it says unflattering things about designs as well as about factories.
The sequence, and where it goes wrong
A rigid multilayer board passes through inner-layer imaging, lamination, drilling, plating, outer-layer imaging, solder mask, surface finish, routing and electrical test. Each stage can only fix its own defects; none can fix the previous one.
That is the organising principle of this section. A drill breaks out of a pad because the annular ring was thin, which is an imaging decision, which is a design decision. The drill is where it becomes visible, not where it becomes true.
Where to start
Lamination and its failure modes
The stage with the least visibility and the highest cost of failure on a high-layer build. Why high-layer boards delaminate covers the five mechanisms — moisture, resin flow, bonding surface, press profile, copper imbalance — and the four of them that are decided before the press.
The stackup that will be built
Lamination is only as good as the construction it is given. The reference stackup builds for 4, 6 and 8 layers gives arrangements that can be handed to a fabricator, with the thickness and impedance consequences stated, and the symmetry rules that keep a panel flat.
The cost side of the process
Process tiers, not layer counts, drive most of the price difference between two quotes for the same board. Why quotes keep expiring covers how material movement reaches a quotation, and the CCL timeline records what the laminate market has done through 2026.
What is checked before the files are opened
The defects that stop a package at review are mostly geometric and mostly the designer's to fix. The twelve Gerber defects lists them with who fixes each one, and the DFM section covers the decisions that set the price before anyone quotes.
The limits worth asking about
A capability table is a summary of a process, and summaries hide the interesting part. Four limits are worth asking about explicitly, because each one has a range rather than a value.
Minimum annular ring, and whether it is held at the drilled size or the finished size. Minimum copper-to-edge distance, and whether routing or scoring sets it. Maximum aspect ratio, which is what actually limits layer count at a given thickness. Plating thickness distribution across the panel, which decides whether the thin end of the distribution still meets the class.
Ask for the number and the condition. A supplier who answers both has a process he can describe; one who answers only the number has a datasheet.
There is a fifth question worth asking on a first order, and it is not technical: what does the shop do when a panel fails final inspection. Rework, scrap or ship-with-deviation are three different businesses, and the answer predicts your second order better than any capability table.
What this section will not do
It will not give you a maximum layer count and call it capability. A number without the stackup, the copper weight and the drill geometry attached is not a specification, and a fabricator who leads with one is answering a question you did not ask.
It will also not present a process as risk-free. Plating thickness varies across a panel, registration moves, and drill position is a distribution rather than a point. The honest version of a capability statement describes the range and the control, which is why the pages here quote limits with the conditions attached.
Ask a fabricator what they do when a panel fails final inspection, not whether panels fail. The first answer describes a process; the second describes a sales position.
What we can and cannot do
We build rigid, HDI, flex, rigid-flex and heavy-copper boards, and we will tell you when a requested construction is at the edge of the process rather than inside it — including when that answer costs us the order.
What we cannot do is build to a drawing that contradicts itself, or guarantee an outcome that depends on how the board is stored and assembled after it leaves us. The fabrication side of the order ends at final inspection; the assembly side continues the same board's history, and the assembly section covers where that handover should be specified.