Effects of Laser Ablation on Aluminum Surface Condition and Ultrasonic Bond Interface Formation

Laser ablation is increasingly being considered as a surface-preparation method for aluminum current collectors in electric-vehicle and aerospace battery manufacturing to improve wire bondability, first-pass yield, and reliability. However, conventional shear testing may not fully capture the quality of the bond interface on laser-processed surfaces. In this study, a Taguchi L9 orthogonal-array design of experiments was used to evaluate the effects of laser-ablation parameters on aluminum surfaces and subsequent wire bond formation. Bond performance was assessed through shear testing and microscopy-based surface characterization. Laser ablation generally increased the mean shear force relative to the isopropyl-alcohol-cleaned reference aluminum plate. However, selected conditions exhibited centrally unbonded regions over the most aggressively ablated areas despite maintaining comparatively high shear force. These findings demonstrate that laser ablation can improve bond quality but must be controlled within a validated process window.