Technology and design rules for flexible printed circuits
Downloads
| Name | Type | Size | Download |
|---|---|---|---|
| Technology - Flexible Printed Circuits(267,98 KB, PDF) | 268 KB | Download | |
| Layer Stack-Ups - Flexible Circuit Boards - Rev 4.0(124,54 KB, PDF) | 125 KB | Download | |
| Suggestions - Flexible Printed Circuits - Excess Length Design(145,17 KB, PDF) | 145 KB | Download | |
| Baking of Flexible- and Rigid-flexible Printed Circuits before Assembly(386,05 KB, PDF) | 386 KB | Download |
Design rules
| Options and Characteristics - Flexible Printed Circuits - Prototypes to Mass Production - FPCs | Online calculation/Standard | on 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 | 230x580mm² | 230x580mm² |
| 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 - FPCs | Online calculation/Standard | on 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 - FPCs | Online calculation/Standard | on 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 - FPCs | Online calculation/Standard | on 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 - FPCs | Online calculation/Standard | on 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 - FPCs | Online calculation/Standard | on explicit enquiry |
|---|---|---|
| Smallest buried via (final diameter) | not possible | 0,20mm |
| Slots (non-plated) - Flexible Printed Circuits - Prototypes to Mass Production - FPCs | Online calculation/Standard | on 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 - FPCs | Online calculation/Standard | on 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 - FPCs | Online calculation/Standard | on 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 - FPCs | Online calculation/Standard | on 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 - FPCs | Online calculation/Standard | on 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 - FPCs | Online calculation/Standard | on 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 - FPCs | Online calculation/Standard | on 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 - FPCs | Online calculation/Standard | on explicit enquiry |
|---|---|---|
| Smallest pad-to-pad distance | not possible | 0,50mm |
| Tolerances, Values, Marks & Norms - Flexible Printed Circuits - Prototypes to Mass Production - FPCs | Online calculation/Standard | on 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 |
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- Circuit boards – green on the outside, also on the inside
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UL approvals for various types of circuit boards
- UL for rigid FR4 PCBs
- UL for flexible circuit boards
- UL for aluminum IMS boards
