PCB manufacturing: choosing the route for your board

Either give us the full stack-up or give us the targets and let our engineers propose one. A full stack-up lists each layer, its copper weight, each dielectric and its thickness, and the finished board thickness. Targets mean layer count, finished thickness, controlled nets and any material you need. Both are valid starting points.

On the advanced route the stack-up is set in review, because laminate choice, via structure and lamination cycles depend on each other. On the standard route, finished thickness and copper weight are declared from fixed options. Either way, the stack-up you approve is the one the board is built to, and it stays attached to the order revision.

The ones the Gerbers cannot carry. Outline tolerance, regular ±0.2 mm or precision ±0.1 mm on the standard route. Finished thickness and its tolerance. Finished hole sizes for press-fit and mounting holes. Impedance targets with their reference layers. Anything else the drawing leaves out is built to the process default.

A drawing that states finished hole sizes, not drill sizes, avoids a frequent mismatch, because plating makes every hole smaller than the drill. Mark which holes are plated and which are not. Mark keep-out zones for stiffeners, card guides and mounting hardware, so the panel and the routing respect them.

Four things, all declared in the configurator. Area and quantity set how many boards fit on a production panel, which is how fabrication is really priced. Layer count sets the lamination and imaging cycles. Feature size decides the process window and the yield. Surface finish decides the chemistry the panel passes through at the end.

Everything else is a smaller adjustment: mask and legend color, finished thickness, outer copper weight, via covering and the electrical test you ask for. Declare them accurately rather than choosing the cheapest of each. A board whose declared configuration does not match its Gerbers has to be priced again after review.

Every order gets a free engineering review, so the question is which choices make it more than routine. On the standard route: 10 or 12 layers, 3 oz outer copper, ENEPIG, 0.10 mm trace and space, Tg 170 laminate, precision outline, filled or capped vias, mixed assembly, several designs per panel, and a regulated product class.

Each of those is flagged in the configurator the moment you select it. On the advanced route, the construction itself is the trigger. Those boards take a longer path because they need deeper process planning, not because they are treated as premium. Boards above 30 layers, copper outside the online options, boards larger than 600 mm per side, and trace and space below 0.10 mm are all priced by an engineer in the official quote.

Choose the aluminum core when the board's job includes moving heat out of a part and into a chassis: LED arrays, motor drivers, power supplies. The metal conducts heat far better than glass-reinforced epoxy, but an aluminum-core board carries its parts on one side. Choose FR-4 for everything else, and high-Tg FR-4 for repeated reflow or hot service.

Both are standard-route options, so both are configured and priced the same way. Laminate glass-transition temperature is declared separately, in three bands, and the highest band goes to review. For boards where heat is the main job, see metal-core PCB.

Targets, not hopes. Name each controlled net, its target impedance and its reference layers in the stack-up notes. Our engineers check the stack-up and trace widths against the targets before fabrication. We hold impedance to ±5 % and verify it by TDR on test coupons, so the result is measured, not assumed.

A hybrid stack-up is one answer for RF boards: low-loss laminate on the RF layers and FR-4 on the digital layers. It saves cost but needs careful lamination, because the two materials expand differently. Read the high-speed stack-up design guide before you fix the layer order.