Data
Gerber or ODB++, drill, stackup and BOM with manufacturer part numbers.
Stackup and finish
Layer count, copper weight, material and finish confirmed before tooling. Impedance targets stated with the reference layer.
Assembly instruction
Which side is populated, the polarity conventions, test requirements and any parts supplied by the customer.
Logistics
Shipping terms and documentation agreed up front; a fast build still waits at customs if the paperwork is incomplete.


