Technology and design rules for flexible printed circuits

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Technology - Flexible Printed Circuits - Rev 230808(53,11 KB, PDF)PDF53 KB Download
Layer Stack-Ups - Flexible Circuit Boards - Rev 3.3(120,77 KB, PDF)PDF121 KB Download
Suggestions - Flexible Printed Circuits - Excess Length Design - Rev 1.3(171,51 KB, PDF)PDF172 KB Download
Baking of Flexible- and Rigid-flexible Printed Circuits before Assembly - Rev 1.3(185,74 KB, PDF)PDF186 KB Download
Design rules
Options and Characteristics - Flexible Printed Circuits - Prototypes to Mass Production - FPCsOnline calculation/Standardon explicit enquiry
Quantity 1 piece to 1m² total area from 1 piece to mass production
Number of layers 1 to 2 layers up to 6 layers
Material thickness 65µm or 45µm respectively 25µm to 0,30mm
Copper thickness (base) 18µm or 28~35µm*
*2layer standard starting from 18µm base copper, plated up to ~28µm
5µm, 9µm, 12µm, 18µm, 28~35µm*
*2layer standard starting from 18µm base copper, plated up to ~28µm
Material colour beige/fawn beige/fawn
Base material Polyimid with epoxy adhesive adesive-less polyimide (PI), polyethylen (PET)
Operating temperature around 120° C up to around 200° C (Tg 260), adesive-less polyimide (PI)
Copper type no selection Elektrolytic deposit (ED) or rolled annealed (RA)
Silk print layer none, Top none, top, bottom, double sided
Solder mask colour cover lay, yellow green solder mask
Cover lay yellow polyimide yellow, black or white polyimide
Combination solder mask & cover lay possible possible
Silk print colour white black, blue, yellow, white, red
Via-Filling (no copper lid) possible (with cover lay) possible (with cover lay)
Stiffener for standard ZIF/LIF connector 0,30mm +/-0,05mm several thicknesses, FR4 or polyimide
3M-adhesive possible possible
E-Test possible possible
Plugging Plugging (with copper lid, e.g. for „via-in-pad“ technology) not possible not possible
Peelable mask not possible possible (stiffeners)
Chamfering/beveling not possible not possible
Surface finish immersion gold (ENIG) immersion tin, immersion gold (ENIG), immersion silver, OSP
Connector gold plating not possible possible
Long term tempering not possible possible
Maximum FPC size 1 and 2 layers 235x585mm² 235x585mm²
Maximum FPC size 4 and 6 layers not possible 220x320mm²
Lead time options 1- and 2 layers FPCs 5WD, 7WD, 9WD, 12WD, 17WD, 22WD from 3WD
Lead time options 4- and 6 layers FPCs not possible from 10WD
Routing not possible not possible
V-Cut / scoring not possible possible, inside fixture/stiffener
Jump scoring not possible not possible
Punching (soft tooling) standard possible
Punching (hard tooling) not possible possible
Hand Cut not possible possible
Hand cut & soft tooling combination not possible possible
Counter sink drills / tapped holes not possible not possible
Special multilayer stack-ups not possible possible
Panel production - Flexible Printed Circuits - Prototypes to Mass Production - FPCsOnline calculation/Standardon explicit enquiry
V-Cut / scoring panel not possible possible
V-Cut - punching panel (combination) not possible possible
Multi Panel (more than one 1 layout on a panel) not possible possible
Panel setup (chosen by LeitOn) possible possible
Panel setup (according to drawing) not possible possible
PTH-drills (plated drills) - Flexible Printed Circuits - Prototypes to Mass Production - FPCsOnline calculation/Standardon explicit enquiry
Smallest Drill 5µm to 18µm (final diameter) not possible 0,15mm
Smallest Drill 28~35µm (final diameter) 0,25mm 0,15mm
Smallest Drill 70µm (final diameter) not possible 0,20mm
Smallest annular ring 5µm to 18µm not possible 0,10mm
Smallest annular ring 28~35µm 0,15mm 0,10mm
Smallest annular ring 70µm not possible 0,15mm
Possible drill sizes up to 5,5mm in 0,05mm steps up to 5,5mm in 0,05mm steps
drills >5,5mm punched punched
Smallest hole-to-hole distance for 0,2mm to 2,0mm drill diameter (outer edge to outer edge) 0,50mm 0,40mm
Smallest hole-to-hole distance for 2,05mm to 5,5mm drill diameter (outer edge to outer edge) 0,60mm 0,50mm
Intersecting drills not possible replaced by punching
Half open drills on PCB edge (Half open PTH) not possible possible
NPTH-drills (non-plated drills) - Flexible Printed Circuits - Prototypes to Mass Production - FPCsOnline calculation/Standardon explicit enquiry
Smallest drill size (final diameter) 0,40mm 0,30mm
Possible drill sizes 0,40mm to 5,5mm in 0,05mm steps 0,30mm to 5,5mm in 0,05mm steps
Copper clearance / distance to copper 0,25mm 0,20mm
Drills >5,5mm punched punched
Smallest distance from drill to outer edge 0,60mm 0,50mm
Smallest hole-to-hole distance for 0,2mm to 2,0mm drill diameter (outer edge to outer edge) 0,50mm 0,40mm
mallest hole-to-hole distance for 2,05mm to 5,5mm drill diameter (outer edge to outer edge) 0,60mm 0,50mm
Intersecting drills not possible replaced by punching
NPTH drills in copper area (without clearance) not possible (copper will be cleared by min. 0,25mm) on explicit notification
Blind Vias - Flexible Printed Circuits - Prototypes to Mass Production - FPCsOnline calculation/Standardon explicit enquiry
Smallest blind via (final diameter) not possible 0,20mm
Smallest Aspect-Ratio not possible 1
Smallest annular ring not possible 0,15mm
Buried Vias - Flexible Printed Circuits - Prototypes to Mass Production - FPCsOnline calculation/Standardon explicit enquiry
Smallest buried via (final diameter) not possible 0,20mm
Slots (non-plated) - Flexible Printed Circuits - Prototypes to Mass Production - FPCsOnline calculation/Standardon explicit enquiry
Inner slots NPTH by punching or hand cut Hard tool punching
Smallest inner slot NPTH from 1,0mm up, punching or by hand cut from 0,5mm up, hard tool punching
Smallest radius (inner corners) NPTH right angle acute angle
Slots (plated) - Flexible Printed Circuits - Prototypes to Mass Production - FPCsOnline calculation/Standardon explicit enquiry
Inner slots PTH not possible possible
Smallest inner slot PTH not possible from 0,5mm hard tool punching
Edge plating (outer edge) not possible possible
Special outline paths with plating (inner) not possible possible
Smallest radius (inner corner, final) PTH not possible right angle
Smallest annular ring not possible 0,15mm
Copper Layers (outer) - Flexible Printed Circuits - Prototypes to Mass Production - FPCsOnline calculation/Standardon explicit enquiry
Smallest trace 5µm not possible 0,03mm
Smallest trace 9µm not possible 0,06mm
Smallest trace 18µm not possible 0,09mm
Smallest trace 28~35µm 0,10mm oder 0,15mm 0,10mm
Smallest trace 70µm not possible 0,20mm
Smallest trace-to-trace distance 18µm not possible 0,09mm
Smallest trace-to-trace distance 28~35µm 0,10mm oder 0,15mm 0,10mm
Smallest trace-to-trace distance 70µm not possible 0,20mm
Smallest drill-pad diameter 0,55mm 0,40mm
Smallest copper clearance to inner edges (slots) 0,25mm 0,20mm oder 0,0mm (plated)
Smallest copper clearance to outer edges 0,25mm 0,20mm oder 0,0mm (metallisiert)
Smallest copper clearance to outer edges (V-Cut) not possible 0,50mm
Copper Layers (inner) - Multilayer Flexible Printed Circuits - Prototypes to Mass Production - FPCsOnline calculation/Standardon explicit enquiry
Smallest trace 5 to 9µm not possible 0,04mm
Smallest trace 18µm not possible 0,09mm
Smallest trace 28~35µm not possible 0,10mm
Smallest trace 70µm not possible 0,20mm
Smallest trace-to-trace distance 5 to 9µm not possible 0,04mm
Smallest trace-to-trace distance 18µm not possible 0,09mm
Smallest trace-to-trace distance 28~35µm not possible 0,10mm
Smallest trace-to-trace distance 70µm not possible 0,20mm
Smallest drill-pad diameter not possible 0,40mm
Smallest copper clearance to outer edges not possible 0,30mm
Smallest copper clearance to inner edges (slots) not possible 0,35mm
Smallest copper clearance to drills not possible 0,30mm
Solder Mask - Flexible Printed Circuits - Prototypes to Mass Production - FPCsOnline calculation/Standardon explicit enquiry
Smallest solder mask web (straight) 0,10mm 0,10mm
Smallest solder mask web (round) 0,08mm 0,08mm
Smallest size around copper pad 0,05mm <0mm
Smallest text lines 0,25mm 0,25mm
Cover Lay (punched / drilled / lasered) - Flexible Printed Circuits - Prototypes to Mass Production - FPCsOnline calculation/Standardon explicit enquiry
Smallest rectangular pad (clearance) 5x5mm 2x2mm
Smallest cover lay web (straight) 5,0mm 2,0mm
Smallest cover lay web (round) 3,0mm 1,0mm
Smallest size around copper pad 0,2mm <0mm
Smallest text lines not possible not possible
Silk Print - Flexible Printed Circuits - Prototypes to Mass Production - FPCsOnline calculation/Standardon explicit enquiry
Smallest lines 0,20mm 0,15mm
Smallest distance between lines 0,20mm 0,15mm
Minimum clearance to copper pads 0,20mm 0,15mm
Carbon Print - Flexible Printed Circuits - Prototypes to Mass Production - FPCsOnline calculation/Standardon explicit enquiry
Smallest pad-to-pad distance not possible 0,50mm
Tolerances, Values, Marks & Norms - Flexible Printed Circuits - Prototypes to Mass Production - FPCsOnline calculation/Standardon explicit enquiry
Max. offset drill centre to centre of reference 0,10mm 0,075mm
Max. offset solder stop (laquer or cover lay) / copper structures 0,20mm 0,10mm
Finished drill sizes PTH (up to 3mm) -0,05/+0,10mm -0/+0,10mm
Finished drill sizes PTH (> 3mm) -0,05/+0,10mm -0/+0,10mm
Finished drill sizes NPTH (up to 6mm) -0,05/+0,10mm -0/+0,10mm
Finished drill sizes NPTH (>6mm) -0,05/+0,10mm -0/+0,10mm
Outline +/-0,30mm +/-0,10mm
Max. offset outline/copper structures +/-0,30mm +/-0,10mm
Scoring depth not possible +/-0,20mm
Max. offset scoring/copper structures not possible +/-0,20mm
Etch tolerance copper thickness 5µm not possible +0/-0,01mm
Etch tolerance copper thickness 9µm not possible +0/-0,01mm
Etch tolerance copper thickness 18µm not possible +0/-0,02mm
Etch tolerance copper thickness 28~35µm +0/-0,03mm +0/-0,03mm
Etch tolerance copper thickness 70µm not possible +0/-0,04mm
Material thickness tolerance +/-15% differs, please enquire
Copper thickness tolerance +/-15% +/-10%
Thickness immersion tin >= 0,5µm >= 1,0µm
Thickness tin (HAL-lead free) not possible nicht möglich
Immersion gold for soldering purpose (nickel thickness) 1,5µm to 3µm 2,5µm to 5µm
Immersion gold for soldering purpose (gold thickness) 0,025µm to 0,075µm 0,05µm to 0,075µm
Immersion gold for gold-wire bonding (nickel thickness) not possible not possible
Immersion gold for gold-wire bonding (gold thickness) not possible not possible
Immersion gold for aluminium-wire bonding (nickel thickness) 1,5µm to 3µm 2,5µm to 5µm
Immersion gold for aluminium-wire bonding (gold thichicht) 0,025µm to 0,075µm 0,05µm to 0,075µm
Elctrolytic soft gold for connectors, soft, bonding (nickel thickness) not possible 4µm to 8µm
Elctrolytic soft gold for connectors, soft, bonding (gold thickness) not possible 0,2µm to 0,3µm
Elctrolytic hard gold for connectors, hard, no bonding (nickel thickness) not possible 4µm to 8µm
Elctrolytic hard gold for connectors, hard, no bonding (gold thickness) not possible 0,8µm to 1µm
Solder mask thickness ca. 10µm >15µm
Cover lay thickness 25,4µm from 12,5µm
Adhesive thickness Polyimid base material to copper (epoxy) 25,4µm from 12,5µm
Adhesive thickness Polyimid-cover lay to copper 25,4µm from 12,5µm
Copper thickness inside plated holes (PTH) 5µm to18µm at least 6µm at least 6µm
Copper thickness inside plated holes (PTH) 28~35µm at least 10µm at least 10µm
Copper thickness inside plated holes (PTH) 70µm at least 12µm at least 12µm
Connector tolerance with siffener (total width) +/-0,15mm +/-0,075mm
Connector tolerance with siffener (outline to pad) +/-0,15mm +/-0,075mm
Chamfer angle not possible not possible
Base material RoHS-compliant yes alway yes alway
Surface finish RoHS-compliant yes alway yes alway
IPC-norm some IPC-6013 - Class 1, 2 or 3
UL-certification of FPC (UL-number, Logo, datecode) not possible possible
UL-certification of FPC base material some possible
Insert date code (WW/YY) possible, please advise in case of order/enquiry possible, please advise in case of order/enquiry
Insert supplier logo (LeitOn) possible, please advise in case of order/enquiry possible, please advise in case of order/enquiry
DIN EN ISO 9001 certification for order preparation, CAM and order processing from LeitOn yes yes
DIN EN ISO 9001 certification FPC supplier yes yes
DIN EN ISO 14001 certification FPC supplier no possible
DIN EN ISO 16949 certification FPC supplier no possible
Climate-neutral operation
since 2021
  • CO2 neutral through compensation
  • Circuit boards – green on the outside, also on the inside
Member of the Fachverband Elektronik-Design
  • Expertise through active exchange
  • Expertise through training and further education
ISO tested by the most renowned auditor in Germany
  • ISO 9001:2015 Quality Management
  • ISO 14001:2015 Environmental Management
UL approvals for various types of circuit boards
  • UL for rigid FR4 PCBs
  • UL for flexible circuit boards
  • UL for aluminum IMS boards