Flexible flat cable replaced the round loom inside every thin device: laminated parallel conductors, millimeters of thickness, and connectors that clamp rather than solder. FFC is one of the highest-volume cable products in electronics, and its specifications are simple once organized. This guide is that organization.
Construction
FFC sandwiches parallel flat copper conductors between two insulation films (PET typically, polyimide for temperature), bonded with adhesive. The laminated structure gives FFC its virtues: constant conductor spacing (controlled geometry without effort), minimal thickness (0.1-0.3mm class), flexibility in one plane, and mass terminability via insulation displacement. Conductor count runs from 4 to 60+; pitch from 0.5mm (dominant) to 2.54mm.
The Specification Set
An FFC is fully specified by a short list — get it right and ordering is trivial:
- Pitch: 0.5mm, 1.0mm, 1.25mm, 2.54mm — must match the connector exactly.
- Conductor count: circuits required, plus grounds for signal assemblies.
- Length: cut length including exposed conductor ends; electrically, shorter is always better — FFC is unshielded parallel structure.
- Exposure type: type A (same side) or type B (opposite sides) — must match the connector's contact geometry; this is the most common ordering error.
- Stiffener: reinforcement laminated at the ends for insertion support and thickness matching — required by ZIF connectors, optional elsewhere.
- Thickness: standard ~0.3mm class at 0.5mm pitch with stiffeners to 0.5mm+; ZIF clamping ranges are tight.
Connector Compatibility
FFC mates ZIF/LIF connectors: the cable slides in and a locking cam clamps the conductors against contacts. Compatibility checks beyond pitch: contact width vs conductor width, clamping range vs cable+stiffener thickness, exposure side, and contact style (bottom-contact vs top-contact connectors flip the required exposure — check, don't assume). Connector cycle ratings matter for serviceable designs: ZIF cams and contacts wear with re-insertion, and our FFC/FPC assembly guide covers the selection detail.
Routing Rules
FFC routing has three non-negotiables. Bend radius: the cable bends in one plane only, and the minimum radius (typically 10x thickness for static, more for dynamic) protects the conductors from work-hardening fractures at the fold. Twist discipline: FFC can be twisted 90° at a defined point for routing changes, but the twist zone needs length and support. Strain isolation: routing must keep flex loads off the connector interface — anchoring near (not at) the connector, with slack absorbing movement.
Applications
- Consumer electronics: displays, printers, cameras — the birthplace and still the volume base.
- Automotive: display and module links in flat-construction form (our automotive FFC guide covers the environmental upgrades).
- Industrial: panel displays, scanner heads, compact instruments.
- Medical: compact diagnostic devices where height budget rules.
Kaweei FFC Supply and Custom Assembly
Kaweei supplies standard FFC in all pitches and exposure types, cut and stiffened to specification, and integrates FFC into custom assemblies with connectors and routing hardware. Contact us with your pitch, count, length and exposure type; for signal-critical flat links, our high-speed harness guide covers the validation side.