Bendability enhancement of 3D interconnections with out-of-plane corrugation for flexible hybrid electronics

This study focuses on enhancing the bendability of flexible interconnects with out-of-plane corrugation for flexible hybrid electronics. We propose two typical configurations of 3D corrugated interconnects: serpentine and trapezoidal. Three methods are introduced to fabricate these corrugated interconnects. The advantages and drawbacks of each fabrication strategy are discussed, and the impact of the 3D corrugation geometry and material on bendability is elucidated. In addition, the material properties of two types of negative photosensitive materials, SU-8 and F-PD (flexible-photoimageable dielectric), are compared. Results show that the resistance increase of 3D corrugated interconnects after a 5 mm radius bending test is drastically lower (by approximately 1900%-2000%) than that of conventional 2D planar interconnects.