ILFA design rules for rigid-flex PCBs
ILFA PCBs
General design rules
LEGEND STANDARD HIGH END (ON REQUEST)
Max. PCB dimensions 420x570mm On request
Thickness rigid-flex A 0.4 - 4.2mm On request
Metallized holes & milled cut-outs (details refer to the diameter of the drilling tool)
Drilling tool diameter Deviations possible with press-fit technology Specified end diameter + 100 µm On request
Through hole 1 Aspect ratio 1:8, minimum Ø 100 µm Aspect ratio 1:10, minimum Ø 100 µm
Through hole, plugged and capped ¹ 2 Aspect ratio 1:8, minimum Ø 150 µm Aspect ratio 1:10, minimum Ø 100 µm
Edge metallizations 3 min. 2.0 mm distance from the flexible area
Conductive pattern / remnant annular rings
Trace width on inner & outer layers (µm) Depending on copper thickness B Without plugging ≥75 with plugging ≥100 Without plugging ≥50 with plugging ≥75
Conductor spacing on inner & outer layers (µm) Depending on copper thickness C Without plugging ≥75 with plugging ≥100 Without plugging ≥50 with plugging ≥75
Annular ring between end-Ø inner and outer layers (µm) D ≥150 On request
Distance from hole to hole (µm) Based on end- Ø E ≥300 On request
Distance bore to adjacent conductive pattern (µm) Based on end- Ø F ≥250 On request
Overlap of edge metallization on outer layer (µm) On inner layer recommended G ≥300
Distance of conductive pattern to milling contour (µm) H ≥300 ≥100
Distance from hole to milling contour (µm) Based on end- Ø I ≥400 On request
Soldermask
Soldermask fillet width (µm) Depending on solder mask type, colour, copper thickness J ≥80 ≥70
Soldermask clearance to copper (µm) K ≥50 ≥25
Soldermask overlap solder mask defined pads (µm) L ≥50 ≥25
Soldermask clearance of edge metallization (µm) M ≥100 On request
Soldermask clearance via / component bore unplugged (µm) N ≥70 On request
Special rigid-flex design rules
Distance from bore to flex area (µm) Based on end- Ø O ≥700
Length of flex area (µm) P ≥2000
Overlap of of coverlay with rigid area (µm) Q 500 500 - 1000
Minimum bending radius² single bend (mm) Without back bend Thickness of flexible area X 1 On request
Minimum bending radius² 4-12 cycles (mm) Thickness of flexible area X 6 On request
Minimum bending radius² dyn. stress (mm) Thickness of flexible area X ≥10 On request
¹Plugging is possible from a circuit board thickness of ≥0.3 mm excl. copper thickness. PCBs with external, flexible base materials, or materials without glass fabric cannot be plugged.
² Bending radius: Thickness of the flexible area = addition of all materials (coverlay, adhesive, copper, base material). The information is only valid for a flexible core with maximum two copper layers.
VERSION: ILFA DRF1

Download design rules for rigid-flex PCB´s here.