Flexible Interconnection
Flexible substrate comprises a thin, high-performance polyimide film pattern with copper conductors designed to connect electronic components across curved surfaces or moving joints. The polyimide flex circuit governs the routing of electrical signals in compact or high-vibration sensor assemblies. It stops applying if the operating temperature exceeds the continuous use limits of the polyimide resin.
Bending Fatigue
Dynamic applications demand high resistance to repeated deformation. A polyimide flex circuit can withstand millions of flexural cycles without cracking the copper traces, provided that the bend radius is kept within recommended limits. Designers must specify the thickness of both the polyimide film and the copper foil to prevent premature fatigue failure.
Signal Integrity
Electromagnetic shielding can be integrated directly into the flexible substrate. By incorporating ground planes or shield layers, the polyimide flex circuit protects sensitive sensor signals from external electromagnetic interference. This is essential when the sensor is located far from the main processing board.
Thermal Limits
Assembly processes must respect the thermal limits of the substrate materials. While the polyimide flex circuit is highly heat resistant, the adhesive layers used to laminate the copper traces can degrade during prolonged exposure to high reflow temperatures. Moisture pre-baking is required before assembly to prevent delamination.
