You Don't Have to Strain Yourself Over Marking Issues

摘要

Is a bead of strain relief required at every rigid flex interface on a rigid flex circuit? Strain relief is a very common feature on rigid flex circuits. The most common material for this application is a semi-rigid epoxy. Because the epoxy stays somewhat flexible, it provides a nice transition between the rigid material and the flex material and reduces the chance for a tear to form in the flex material. The edges of rigid material such as polyimide, BT, or FR-4 epoxy can be very sharp and can act as a shear on the flex material if any type of twisting force is placed on the flex arms. The epoxy strain relief bonds to both the flex and rigid material and greatly reduces the shearing forces. A strain relief bead can also be used to protect the flexible areas of a single-, double-, or multilayer flex circuit with stiffeners.