Metal

Metallurgy

Materials science

Bending

Layer (electronics)

Polyimide

BPDA

Composite material

Journal of Adhesion Science and Technology

The peel strength and peel angle of Cr/BPDA-PDA interfaces were measured using the T-peel test for Cu/Cr/BPDA-PDA structures. When the Cu/Cr metal film was thin, plastic bending of the metal film occurred during the T-peel test. With a thicker metal film, however, plastic bending of BPDA-PDA polyimide was observed. The critical thickness of the metal film for the transition from metal film bending to polyimide bending became thinner with decreasing yield strength of the metal film. Regardless of the metal film bending or polyimide bending during the T-peel test, the peel strength increased with higher peel angle and the failure mode of the Cr/BPDA-PDA interfaces was cohesive failure within BPDA-PDA.

Peel strength and peel angle measured by the T-peel test on Cr/BPDA-PDA interfaces