Once pressed, these panels look just like double sided laminate and are ready for drilling. For double-sided panels, drilling is the 1st process. The panels are pinned to the table of a CNC drill. A Maximum load size is 15 panels up. The panels are deburred after drilling.
Electroless copper is next.
It is developed, and then it goes into a copper plating procedure. The panels are cleaned and activated chemically, then connected to a rack inside a large volume of copper solution. Then, tin is plated on top of the copper. After plating, the DuPont dry film plating resist is stripped off the panel leaving exposed copper. This copper is chemically etched off the panel leaving only the tin over copper circuitry.