ELECTRONICS INDUSTRIES Sectional Design …

1 IPC-2223 BSectional Design Standardfor flexible printed BoardsDeveloped by the flexible Circuits Design Subcommittee (D-11) of theFlexible Circuits Committee (D-10) of IPCU sers of this publication are encouraged to participate in thedevelopment of future :IPC3000 Lakeside Drive, Suite 309 SBannockburn, Illinois60015-1249 Tel 847 847 :IPC-2223A - June 2004 IPC-2223 - November 1998 IPC-D-249 - January 1987 ASSOCIATION CONNECTINGELECTRONICS INDUSTRIES Table of .. of Products .. board Type .. Uses .. Level Changes .. 32 APPLICABLE .. Industry standards .. 43 GENERAL Modeling .. Layout .. Layout Efficiency (ConsiderFinal Panelization) .. Drawing Recommendations .. Requirement Considerations .. Selection .. Options .. Materials (Including Prepregand Adhesives) .. Bonding Material (Prepreg) .. (Liquid) .. Adhesive Bonding Films(Cast Adhesive or Bondply).

2 Anisotropic Adhesives .. Materials .. Materials (Surface Finishes) .. Copper Plating .. Plating .. Plating .. Coating .. Metallic Coatings .. Component Materials(Buried Resistors and Capacitors) .. Coatings for Shielding .. Protective Coatings .. Mask .. Coating .. and Legend .. 95 MECHANICAL AND PHYSICAL Requirements .. PB Fabrication .. to Roll Fabrication .. Configuration .. Profile (Outline) .. Area Considerations .. Areas .. Bend .. Lengths .. Plane .. and Heat Sinks .. (Strain Relief) .. Requirements .. Considerations .. flexible and Rigid Flex PBs .. flexible and Rigid Flex PBs .. Preheats and Reflow .. Features .. 206 ELECTRICAL Considerations .. and Capacitance Control .. 207 THERMAL 208 COMPONENT AND ASSEMBLY Placement Requirements .. Surface Mount Requirements.

3 For Surface Mounting .. on Mounting to flexible Sections .. Connections .. Lands .. 219 Requirements for Lands with Holes .. Requirements .. Ring Requirements .. or Standoff Land Area Considerations .. Size for Non-Plated Component Holes .. Size for Plated-Through ComponentHoles .. 21 May Relief in Conductor Planes .. Mount Components .. Lands .. Transition .. Unsupported Edge Conductors/Fingers .. Component Holes .. Component Holes .. Access Openings .. Access, Unsupported Lands .. Access, Holes .. Access Spacing .. Access/Exposed Lands .. 1 Land Access, Opposite Sides .. 2410 Characteristics .. Conductor Routing .. Conductor Edge Spacing .. Characteristics .. Conductive Areas .. 2512 QUALITY 25 FiguresFigure 1-1 Type 1 Single-sided flexible PB -Adhesive Substrate Construction .. 1 Figure 1-2 Type 1 Single Sided flexible PB -Adhesiveless Substrate Construction.

4 1 Figure 1-3 Type 2 Double-sided flexible PB -Adhesive Substrate Construction .. 1 Figure 1-4 Type 2 Double-sided flexible PB -Adhesiveless Substrate Construction .. 1 Figure 1-5 Type 3 Multilayer flexible PB -Adhesive Substrate Construction .. 2 Figure 1-6 Type 3 Multilayer flexible PB -Adhesiveless Substrate Construction .. 2 Figure 1-7 Type 4 Rigid-flex PB - AdhesiveSubstrate Construction .. 2 Figure 1-8 Type 4 Rigid-flex PB - AdhesivelessSubstrate Construction .. 2 Figure 1-9 Type 5 flexible or Rigid-flex PBwithout Plated-through Holes -Adhesive Substrate Construction .. 3 Figure 1-10 Type 5 flexible or Rigid-flex PBwithout Plated-through Holes -Adhesiveless Substrate Construction .. 3 Figure 3-1 Dimensional Modeling .. 4 Figure 3-2 Final Panelization .. 4 Figure 4-1 flexible Cross-SectionalConstruction Examples .. 5 Figure 4-2 Unbonded Flex Cross-SectionalConstruction of Rigid Flex.

5 6 Figure 4-3 Plating for Adhesiveless SubstrateApplications .. 9 Figure 4-4 Selective Plating for AdhesiveSubstrate Applications .. 9 Figure 5-1 Circuits Nested on a Panel .. 10 Figure 5-2 Special flexible PB Features .. 10 Figure 5-3 Cutout with a Drilled Hole .. 10 Figure 5-4 Reinforcement Patch for Flex Area .. 10 Figure 5-5 Slits and Slots .. 11 Figure 5-6 Spacing of Plated-Through Holefrom Rigid to Flex Interface .. 11 Figure 5-7 Reduced Bend Radii .. 12 Figure 5-8 Conductors in Bend Areas .. 13 Figure 5-9 Bend/Crease Areas Center Lines .. 13 Figure 5-10 Neutral Axis Ideal Construction .. 13 Figure 5-11 Stresses on Layers During Folding(Adhesive Substrate Constructions) .. 14 Figure 5-12 Stresses on Layers During Folding(Adhesiveless Substrate Constructions) .. 15 Figure 5-13 Fold Back .. 16 Figure 5-14 Irregular Folds .. 16 Figure 5-15 Differential PB Lengths.

6 17 Figure 5-16 Differential PB Lengths, Rigid-Flex .. 17 Figure 5-17 Bookbinder .. 18 Figure 5-18 Typical Example of Copper Removalfor flexible Shielding .. 19 Figure 5-19 Adhesive Fillets (Strain Relief) .. 19 Figure 5-20 Establishing Datums .. 20 Figure 9-1 Conductor to Land Transitions .. 21 Figure 9-2 Coverlay Access Openings andExposed Unsupported Lands .. 23 Figure 9-3 Coverlay Access Opening forUnsupported Lands .. 23 Figure 9-4 Coverlay Access Openings andExposed Supported Lands .. 24 Figure 10-1 Conductor Routing, Rigid-Flex Transition .. 24 TablesTable 4-1 Characteristics of Typical flexible DielectricsTable 4-2 Minimum Average Copper Thickness, mm [in] . 8 Table 9-1 Minimum Standard Fabrication Allowancefor Interconnection Lands, mm [in] .. 21 Table 9-2 Nonfunctional Land Considerations .. 22 IPC-2223 BMay 2008viSectional Design Standard for flexible printed Boards1 SCOPEThis standard establishes the specific requirements for thedesign of flexible printed circuit applications and its formsof component mounting and interconnecting flexible materials used in the structures are comprisedof insulating films, reinforced and/or non-reinforced,dielectric in combination with metallic materials.

7 Theseinterconnecting boards may contain single, double, multi-layer, or multiple conductive layers and can be comprisedwholly of flex or a combination of both flex and PurposeThe requirements contained herein areintended to establish specific Design details thatshallbeused in conjunction with IPC-2221 and may also be used inconjunction with IPC-2222 for the rigid sections of rigid-flex Classification of ProductsClassification type anduse of productsshallbe in accordance with IPC-2221 andas stated in and printed board TypeThis standard provides designinformation for different flexible and rigid-flex printedboard (PB) types. PB types are classified as:Type 1 Single-sided flexible PB containing one conduc-tive layer, with or without stiffener (see Figure 1-1 and Fig-ure 1-2)Type 2 Double-sided flexible PB containing two conduc-tive layers with plated-through holes (PTHs), with or with-out stiffeners (see Figure 1-3 and Figure 1-4)

8 IPC-2223b-1-1 Figure 1-1 Type 1 Single-sided flexible PB - AdhesiveSubstrate ConstructionAccess HoleCoverlayAdhesiveSubstrateCopper PadIPC-2223b-1-2 Figure 1-2 Type 1 Single Sided flexible PB - AdhesivelessSubstrate ConstructionAccess HoleCoverlayAdhesiveAdhesivelessSubstrat eCopper PadIPC-2223b-1-3 Figure 1-3 Type 2 Double-sided flexible PB - AdhesiveSubstrate ConstructionPolyimideSubstrateCopper-Pla tedThrough-HoleCoverlayCopperPadsCoverla yAdhesiveAccess HoleIPC-2223b-1-4 Figure 1-4 Type 2 Double-sided flexible PB - Adhesive-less Substrate ConstructionAccess HoleCoverlayCopperPadsCoverlayCopper-Pla ted Through-HoleAdhesivelessSubstrateAdhesiv eMay 2008 IPC-2223B1