Custom 2-Layer Flexible Circuit Fabrication
Double-Sided Flex PCB Manufacturing
Custom 2-layer flexible circuits for prototype and production orders. PCBELEC manufactures double-sided flex PCBs with plated-through connections, defined coverlay openings, local stiffeners and specified contact finishes.
Send your fabrication package to sales@pcbelec.com
- Circuit Structure Two Copper Layers
- Layer Connections Plated-Through Interconnects
- Manufacturing Orders Prototypes to Production
Double-Sided Flex / 2-Layer FPC
What Is a Double-Sided Flex PCB?
A double-sided flex PCB is a flexible printed circuit with two copper conductor layers on opposite sides of an insulating flexible core. It is also called a double-sided flexible PCB, double-sided FPC or 2-layer flex PCB.
Plated-through holes connect designated top and bottom copper features, giving the layout two routing surfaces within one flexible circuit. Coverlay protects the circuitry while openings expose the required pads and contacts.
PCBELEC manufactures this structure as part of our flexible PCB fabrication service, with defined materials, reinforcement and connection features.
Route on Both Sides
Organize connections across top and bottom copper layers rather than routing every connection on a single surface.
Connect Through the Core
Use plated interconnections to join the specified copper features across the flexible dielectric.
Define the Mechanical Regions
Identify flexible spans, supported connection areas and local thicknesses in the manufacturing drawing.
Two Conductive Layers / One Flexible Core
2-Layer Flex PCB Stackup and Plated Connections
Define the copper, flexible core and protective layers together. Plated-through interconnections join designated top and bottom pads, while coverlay openings expose the required connection areas.
Illustrative Cross-Section / Adhesiveless Base Laminate
Swipe horizontally to view all stackup details.
| Construction Element | Function | Details to Specify |
|---|---|---|
| Top & Bottom Copper | Conductive patterns for routing, pads and copper areas. | Copper type, thickness, circuit data and critical conductor geometry. |
| Flexible Core | Electrical insulation and mechanical support between the two circuit layers. | Material grade, dielectric thickness and base-laminate construction. |
| Bonding Layers | Attach protective films and other defined construction elements. | Adhesive system, thickness and location; identify adhesive-based or adhesiveless base laminate. |
| Coverlay | Insulate and protect designated circuit areas while exposing pads and contacts. | Film and adhesive thicknesses, opening data and registration requirements. |
| Plated Interconnections | Connect designated top and bottom copper features through the core. | Finished hole sizes, pad geometry, plating and inspection requirements. |
| Local Reinforcement | Support specified contact, connector or component-bearing regions. | Stiffener material, side, outline, thickness and bonding method. |
| Pad & Contact Finish | Provide the specified finish on exposed conductive areas. | Finish type, coverage and coating thickness requirements. |
Coverlay Openings Are Not Bend-Region Definitions
Openings expose specified pads and contacts. A flexible span is a mechanical region and does not automatically require exposed copper or removal of its protective layers. Define both in the drawing. Explore coverlay and circuit protection.
Adhesiveless Base Does Not Mean Adhesive-Free Board
An adhesiveless base laminate describes the copper-to-core construction. Adhesives can still be present in coverlay, bonding and stiffener attachment. Review flex circuit adhesives and bonding materials when defining the complete stackup.
2-Layer Flex Fabrication Specifications
Double-Sided Flex PCB Manufacturing Capabilities
PCBELEC manufactures double-sided flexible circuits with polyimide laminates, plated interconnections, protective coverlay and local reinforcement. Define the copper, thickness and interface features in the fabrication package.
- Circuit Structure 2 Copper Layers
- Maximum Board Size 480 × 1800 mm
- Minimum Board Thickness 0.08 mm ±0.02 mm
Swipe horizontally to view all manufacturing specifications.
| Capability Item | Construction / Process | Manufacturing Specification |
|---|---|---|
| Conductive Layers | Double-sided flexible circuit | Top and bottom copper with plated interconnections |
| Base Materials | Polyimide laminate systems | DuPont PI / Shengyi PI |
| Maximum Board Size | Double-sided flex format | 480 × 1800 mm |
| Minimum Board Thickness | Double-sided flexible construction | 0.08 mm ±0.02 mm |
| Minimum Trace / Space | 1/3 oz or 1/2 oz copper | 0.076 / 0.076 mm |
| Minimum Trace / Space | 1 oz copper | 0.10 / 0.10 mm |
| Minimum CNC-Drilled Hole | Lower-layer-count flex process | 0.20 mm |
| Finished PTH Tolerance | Plated-through holes | ±0.038 mm |
| Minimum Slot Width | Machined slot feature | 0.50 mm |
| Coverlay Registration | Protective film alignment | 0.10 mm registration tolerance |
| Local Reinforcement | Stiffener-supported regions | PI / FR-4 reinforcement |
| Surface Finishes | Exposed pads and contacts | OSP, HASL, ENIG, flash gold and tin finishes |
| Controlled Impedance | Specified impedance structures | ±10% impedance-control capability |
| Profile Tolerance | Outline / contour | ±0.05 mm |
| Inspection & Records | Manufactured bare circuits | Circuit inspection, electrical verification, dimensional checks and microsection reporting |
Routing, Flexible Regions & Connection Interfaces
Choose the Construction for Your Routing and Bend Requirements
Use two copper layers when the routing and interconnection requirements call for them. Define the flexible-region geometry and supported connection areas alongside the electrical structure.
Swipe horizontally to compare flex circuit constructions.
| Construction | Conductive Structure | Selection Focus | Manufacturing Service |
|---|---|---|---|
| Single-Layer Flex PCB | One copper circuit layer on a flexible dielectric. | Evaluate when the required connections fit on one conductive layer. | Single-Layer Flex Manufacturing |
| Double-Sided Flex PCB | Two copper layers with designated plated-through interconnections. | Evaluate when two routing surfaces and layer-to-layer connections meet the design needs. | Current Service |
| Multilayer Flex PCB | Three or more conductive layers in a laminated flexible construction. | Evaluate when routing density or reference-layer requirements call for additional copper layers. | Multilayer Flex Manufacturing |
Static Bend Regions
The flex circuit is bent into its installed shape and remains in position during normal operation. Define the final geometry and the installation sequence.
- Bend location, direction, angle and radius
- Local copper, core and coverlay thicknesses
- Fixing points and supported connection areas
Dynamic Flex Regions
For a circuit that moves repeatedly, specify the motion path and local construction together. Layer count alone does not define dynamic bending performance.
- Motion, travel, bend radius and expected cycles
- Copper type and conductor layout in the moving span
- Attachment points and evaluation requirements
Verify the Manufactured Features
Fabrication Quality and Inspection Records
PCBELEC combines circuit inspection, electrical verification and dimensional checks for double-sided flexible circuits. Inspection connects the two-layer construction and local mechanical features to the released manufacturing requirements.
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01 / TOP & BOTTOM CIRCUITS
Circuit Patterns & Electrical Testing
Optical inspection examines the manufactured copper patterns. Electrical testing checks continuity and isolation across the circuit network, including designated layer-to-layer connections.
- Top- and bottom-layer circuit features
- Open- and short-circuit checks
- Specified impedance verification
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02 / PLATED INTERCONNECTIONS
Hole Geometry & Copper Plating
Hole measurements and cross-sectional inspection examine the features that connect the two copper layers through the flexible core.
- Finished hole dimensions and positions
- Plated-hole cross-sectional features
- Relevant copper and interface measurements
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03 / PROTECTION & CONTACTS
Coverlay & Exposed Connection Areas
Inspect protective-layer placement and the exposed conductive areas that define the soldering pads and connector contacts.
- Coverlay opening and alignment checks
- Exposed pad and contact geometry
- Surface-finish appearance
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04 / LOCAL MECHANICAL FEATURES
Outline, Stiffeners & Thickness
Dimensional inspection checks the finished profile and locally reinforced areas against the mechanical drawing and interface requirements.
- Board outline, slots and mounting features
- Stiffener location and construction
- Specified local and connector-tail thicknesses
Development Builds to Repeat Manufacturing
Double-Sided Flex Prototypes and Production
PCBELEC manufactures 2-layer flexible circuits for engineering samples, pilot runs and production. Keep the selected stackup, mechanical regions and connection requirements aligned as the project moves between builds.
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01 / ENGINEERING EVALUATION
Double-Sided Flex Prototypes
Manufacture initial and revised two-layer flexible circuits for your project evaluation, with the specified copper, core, coverlay and local reinforcement.
- Initial designs and revised circuit layouts
- Defined contacts, holes and flexible regions
- Prototype quantities and required records
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02 / PILOT & SMALL-BATCH BUILDS
Low-Volume Flex Orders
Order double-sided flexible boards for pilot runs and small production batches, with the delivery format and interface details defined for the next manufacturing stage.
- Pilot builds and ongoing small-batch needs
- Individual circuits or array delivery
- Inspection and handling requirements
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03 / RELEASED DESIGNS
Production & Repeat Orders
Manufacture released double-sided flex designs for production quantities and repeat builds, with consistent construction requirements connected to each order.
- Released revisions and material definitions
- Coverlay, stiffener and contact consistency
- Packaging and delivery planning
Custom 2-Layer Flex Circuit Quotation
Request a Double-Sided Flex PCB Quote
Send your two-layer circuit files, construction details and quantity to PCBELEC. Include the coverlay, plated holes, reinforcement and connection requirements with the fabrication data.
What Shapes the Fabrication Price?
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Circuit dimensions, outline complexity, quantity and manufacturing panel utilization.
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Copper thickness, flexible core, adhesive system and coverlay construction.
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Hole geometry, routing features, stiffener arrangement and local thicknesses.
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Contact finish, impedance requirements, critical tolerances and inspection records.
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Delivery format, packaging, destination and requested manufacturing schedule.
Include These Details with Your Inquiry
Manufacturing File RequirementsCircuit Files & Revision
Top and bottom copper, drill data, board profile, drawings and required revision.
Stackup & Materials
Copper, flexible core, adhesive layers and finished flexible-region thickness.
Coverlay & Stiffeners
Opening data, reinforcement material, outline, attachment side and bonding details.
Contacts & Mechanical Interfaces
Contact finish, connector reference, insertion thickness, holes and tolerances.
Bend Conditions & Verification
Flexible-region boundaries, use conditions, bend geometry and required inspection records.
Quantity & Delivery
Prototype or production quantity, delivery format, packaging, destination and target date.
2-Layer Flexible Circuit Questions
Double-Sided Flex PCB FAQ
Answers about two-layer construction, thickness, plated connections, bend regions and manufacturing inquiries.
Discuss your next double-sided flex build:
sales@pcbelec.comIs a double-sided flex PCB the same as a 2-layer FPC?
Yes. Double-sided flex PCB, double-sided flexible circuit and 2-layer FPC describe two conductive copper layers on opposite sides of a flexible insulating core.
Coverlay, adhesive and local stiffeners do not count as additional circuit layers. Review the construction definition for the main features.
How are the two copper layers connected?
Plated-through holes connect designated top and bottom copper pads. Copper on the hole wall forms the conductive path through the flexible core.
See the 2-layer stackup and plated connection diagram for the cross-sectional structure.
When should I choose double-sided rather than single-layer flex?
Evaluate double-sided flex when the circuit needs two routing surfaces and layer-to-layer connections. If the required connections fit on one conductive layer, a single-layer construction is another option.
Compare the flex construction choices, including links to single-layer and multilayer manufacturing services.
How should I specify double-sided flex PCB thickness?
Specify the finished thickness of the flexible span separately from locally reinforced areas. Identify which copper, core, adhesive, coverlay and stiffener layers are included at each measurement location.
For connector tails, define the finished insertion thickness against the selected connector drawing. Review local construction and interface requirements.
Can a double-sided flex circuit be used for repeated bending?
Yes, double-sided flex can be designed for repeated movement. The local stackup, copper type, conductor layout, bend radius and motion conditions all contribute to bending performance.
Provide the movement path, expected cycles and evaluation requirements with the design. Two conductive layers alone do not define a universal bend radius or cycle life.
Does an FR-4 stiffener make the circuit rigid-flex?
No. An FR-4 stiffener adds mechanical support to a flexible circuit region. It does not, by itself, add routed rigid circuit layers. Rigid-flex integrates rigid circuit sections with flexible interconnections.
Explore the flex PCB stiffener guide or our rigid-flex PCB manufacturing service.
Which materials and finishes can I specify?
Our primary flexible laminate systems include DuPont PI and Shengyi PI. Define the copper, bonding layers, coverlay and reinforcement together with the required finish on exposed pads and contacts.
Review the double-sided flex capabilities and detailed flex fabrication specifications.
Do you manufacture prototypes and repeat production orders?
Yes. PCBELEC manufactures double-sided flexible boards for prototype evaluation, pilot runs, low-volume orders and repeat production. Each order identifies the required revision, construction, quantity and delivery needs.
Explore our dedicated flex PCB prototype fabrication service and the production options on this page.
What affects the cost of a double-sided flex PCB?
Cost reflects circuit dimensions, quantity, laminate and copper construction, holes, line geometry, coverlay, stiffeners and surface finish. Panel utilization, verification and delivery requirements also contribute to the quotation.
Send the design files and specifications to request a manufacturing quote.
Which files should I send for a quotation?
Send top and bottom circuit data, drill files, profile and fabrication drawings with the required revision. Include the stackup, coverlay openings, stiffeners, contact details and finished local thicknesses.
Add bend conditions, quantity, delivery format and target date. Review our manufacturing file requirements before submitting the package.