Semi Flex Printed Circuit Boards

Many developers would like to be able to do without plugs, connectors and connecting elements for space reasons and would prefer using a rigid-flexible circuit board. Even though they are absolutely competitive from a system cost point of view, rigid-flexible circuit boards are more elaborate and more expensive than flexible and multilayer units.

ANDUS offers a more cost-effective alternative for narrow project budgets with its semi-flexible circuit board without having to forego the advantages of rigid-flexible technology. The expensive flexible polyimide material is substituted with thin FR-4 here.

The following requirements should be met to be able to use this technology:

•  Bending radius >4 mm
•  No permanent bending strain
•  Semi-flexible layer ideally on the outer layer
•  Semi-flexible layer preferably with 70 µm end copper
•  Filling gaps with copper or expanding conductors to maximum width in the semi-flexible field

This allows even series production of reliable quasi rigid-flexible circuit boards.

Semi Flex
Semi-flexible circuit board for an inductive rotary encoder in automotive steering control