Flexible Circuits Assembly

Flexible Circuits Assembly

Flexible circuits are made from a thin plastic

substrate of polyimide or polyester. The most

widely used material for flexible assemblies is

polyimide (poly im id) because it can withstand

the high temperatures required to solder components

without negative effects. Polyester circuits

shrivel up when exposed to those temperatures

and make them less appropriate for flexible

assemblies. The polyimide material is laminated

to conductive layers and insulating layers with

epoxy or acrylic based adhesives. The final product

is a very thin, typically .010”, overall thickness.

This is the characteristic that makes assembly

on flexible circuits more difficult than traditional

printed circuit boards which are 1/16”

thick and sturdy. The inherent nature of a flexible

circuit demands high attention to handling

during the assembly process. Whether hand soldering

or automated soldering, the circuits must

be supported for consistent results. The discussion

below will focus on the processes that will

make any flexible circuit assembly successful.