Double-Sided OLED Display Substrate Alignment via Segmented FPCB

The flexible printed circuit board is divided into multiple rigid segments connected by flexible joints. Each segment can be rigidly coupled to substrate protrusions, while the flexible joints accommodate substrate curvature without creating continuous bent paths that lead to film lead cracks. This segmentation isolates stress concentration points and prevents crack propagation through the entire connection path.

The connection structure transitions from a two-dimensional planar FPCB to a three-dimensional configuration where rigid segments are positioned at different heights and orientations. The flexible joints enable the FPCB to conform to the curved substrate surface while maintaining rigid connections at coupling points, effectively adding a dimensional degree of freedom to the connection structure.

The FPCB is segmented into rigid portions that can be independently coupled to substrate protrusions. This segmentation allows heat or pressure to be applied locally at each rigid coupling point without the interference of bent sections. The flexible joints remain separate and do not interfere with the heating or pressing process at the rigid connection locations.

Different portions of the FPCB have different mechanical properties: rigid segments for coupling and flexible joints for conforming. This local differentiation allows specific regions to be optimized for their functions - the rigid segments can receive concentrated heat or pressure for reliable bonding, while the flexible joints maintain their conformability without requiring thermal or mechanical intervention.

The substrate edges are segmented into multiple protrusions distributed along the connection interface. This segmentation provides multiple discrete alignment features that can be independently positioned, allowing for precise alignment through a distributed array of simple geometric features rather than complex single-structure alignment mechanisms.

Instead of adding complex alignment structures to the FPCB or substrate, the invention inverts the approach by adding simple protruded portions to the substrates themselves. These protrusions serve as the alignment features, eliminating the need for complex alignment mechanisms on the FPCB side while achieving high precision through the simplicity and distribution of the protrusion features.