Flex Rigid PCB’s

Design Rules for Flex / Flex Rigid PCB’s

ITEM STANDARD
INDUSTRIAL 		ADVANCED
INDUSTRIAL		 SPACE, DEFENSE &
AEROSPACE		  
Default Standard IPC CLASS 2 IPC CLASS 2 IPC CLASS 3 / 3A  
Layer count Upto 18 layers Upto 18 layers Upto 18 layers  
Materials Complete range as per
materials list		  Complete range as per 
materials list		  Complete range as per 
materials list		  
Core / Foil construction Core  Core Core  
Inner layer Line Width / Spacing 100 / 100 microns 100 / 100 microns 100 / 100 microns  
Minimum Inner layer Base copper start 18 microns 18 microns 18 microns  
Maximum Inner layer Base copper start 70 microns 70 microns 70 microns  
Outer layer Line Width / Spacing 100 / 100 microns without Cap plating , 125/125 microns with Cap plating 100 / 100 microns without Cap plating , 125/125 microns with Cap plating 100 / 100 microns without Cap plating , 125/125 microns with Cap plating  
Minimum Outer layer Base copper start 18 microns 18 microns 18 microns  
Maximum Outer layer Base copper start 35 microns 35 microns 35 microns  
Thinnest core (2 mil Flex)
– excluding copper foil		 0.05 mm 0.05 mm 0.05 mm  
Minimum Hole Diameter / Minimum
pad size /PCB thickness		 0.15/0.45/
1.6 mm		 0.15/0.45/
1.6 mm		 0.20/0.61/2.4 mm  
Solder Mask pad size enlarged with
respect to copper pad		 0.051 mm 0.026 mm 0.051 mm  
Solder mask color Green, Blue,
Red Teal		 Green, Blue,
Red, Teal		 Green, Other Mask upon request   
Surface Finish ENIG/ Silver/ Leaded HASL
Hard Gold		  ENIG/ Silver/ Leaded HASL
Hard Gold		 ENIG/ Silver/ Leaded HASL
Hard Gold		  
Controlled Impedance  YES +/- 10% TDR Measured  YES +/- 10% TDR Measured  YES +/- 10% TDR Measured  
Legend  White  White  White  
Automated Serial # printing  Optional  Optional  Yes  
BBT Testing  Flying probe tested
against Netlist		  Flying probe tested 
against Netlist		  Flying probe tested 
against Netlist		  
Via filling  Type VI Type VI Type IV and Type VI  
Via filling with Cap plating including via on pad Type VII Type VII Type VII