Verifying Native Source Files in Design Transfer Packages
Verifying native CAD and firmware source files during design transfer prevents unlinked components, build failures, and costly manufacturing delays.
Silkscreen Clearance
Meaning
Safe distances between printed ink and critical board features prevent manufacturing defects and assembly issues. A silkscreen clearance defines the minimum gap between the white epoxy ink and the edges of solder pads or drilled holes. If the ink overlaps a pad, it can cause poor solder joints or electrical opens.
Maintaining this buffer is a standard part of design for manufacturing rules.
Solderability Protection
Ink on a conductive surface acts as a contaminant during the reflow process. Proper silkscreen clearance ensures that the solder paste adheres directly to the metal finish of the pad. When the ink is too close, it can prevent the solder from wetting correctly, leading to weak mechanical connections.
This is particularly dangerous for small surface-mount components like 0201 resistors. Solder mask openings must remain free of any non-conductive printing.
Assembly Identification
Text and component outlines must remain legible even in dense layouts. The silkscreen clearance keeps labels from being cut off by vias or obscured by other markings. Clear labeling is necessary for manual inspection and field repair.
If the text is too small or crowded, the risk of placing the wrong component increases.
Manufacturing Tolerance
Printers and screens have a limited alignment precision. A generous silkscreen clearance accounts for the slight shifts that occur during the printing process. If the tolerances are too tight, the yield of the board fabrication will drop as more units fail the visual inspection.
Most shops require at least five to ten mils of spacing.