TOP

Top Side Metal

BOTTOM

Bottom Side Metal

INTERNAL

Internal Metal (Positive Polarity)

NEG_PLANE

Plane (Negative Polarity -- Usually contains Thermal Dcodes)

POS_PLANE

Plane (Positive)

DRILL

NC Drill (Should have tools sizes & format embedded inside file)

SILK_TOP

Top Side Silkscreen

SILK_BOTTOM

Bottom Side Silkscreen

MASK_TOP

Top Side SolderMask

MASK_BOTTOM

Bottom Side SolderMask

PASTE_TOP

Top Side Paste

PASTE_BOTTOM

Bottom Side Paste

ROUT

NC Rout (Should have tools sizes & format embedded inside file)

INSULATOR

Insulator Layer

COMPONENTS_TOP

Top side Components (Must be CSV Format Centroid & it will be renamed to "comp_+_top"

COMPONENTS_BOTTOM

Bottom side Components (Must be CSV Format Centroid & it will be renamed to "comp_+_bot"

TEMPORARY

Temporary Layer (Used when the gerber type is unknown)

FAB_DRAWING

Fab Drawing (Used for reference only)

BORDER

PCB Boarder Layer

SCORE        

Score Layer used for Panel Snap-Outs

GRAPHIC

Default Layer (Used when the gerber type is unknown)