F5.1 Silkscreen layer requirements
The silkscreen is printed to the external surface of a PCB to aid in component identification and orientation. Typically this layer contains the component RefDes to locate components on the board after assembly.
KiCad refers to the silkscreen layers as:
-
F.SilkS
- Front silkscreen layer -
B.SilkS
- Back silkscreen layer
The following elements must be provided on the silkscreen.
-
Reference Designator must be drawn on
F.SilkS
layer-
Text size =
1.00mm
-
Text thickness =
0.15mm
-
-
Silkscreen line width is between {
0.10mm
and0.15mm
} as per IPC-7351C:-
Silkscreen line width should nominally be
0.12mm
-
0.1mm
is allowed for high density designs -
0.15mm
is allowed for low density designs
-
-
Silkscreen must not be placed over pads or areas of exposed copper
-
Clearance between silkscreen and exposed copper elements is recommended to be 0.2mm.
-
Clearance must be at least the silkscreen line width or pad mask expansion, whichever is greater.
-
-
For SMD footprints, silkscreen must be fully visible after boards assembly (no silkscreen allowed under component)
-
For THT components, additional silkscreen may be placed under component to aid in assembly process
-
Pin-1 designator is provided on the
F.SilkS
layer -
Pin-1 designator must be visible after board assembly
Examples of silk for non polarized components
Examples of silk for polarized components