Mechanism analysis of dual wavelength laser welding AlN-PC joint based on microtexture treatment

• Published in: Optics and laser technology 2025-02, Vol.181, p.112019, Article 112019
• Main Authors: Sun, Dachao, Jiang, Ning, Ni, Chenyi, Liu, Yayun, Chen, Yani, Jiang, Liwei, Wang, Chuanyang
• Format: Article
• Language: English
• Subjects: AlN ceramics; Chemical bond; Dual wavelength laser welding; Microtexture processing
• ISSN: 0030-3992
• DOI: 10.1016/j.optlastec.2024.112019

[Display omitted] •Bonding and Failure Mechanisms of dual wavelength laser welded joints are studied.•Microtexture treatment effectively improves the mechanical bonding of joints.•Al layer produced by nanosecond pulsed laser ablation enhances laser absorption.•Crack propagation at the interface was analyzed.•There is chemical bonding and elemental diffusion at the AlN-PC joint. High-strength interfacial bonding between ceramics and transparent polymers is hardly to be achieved, especially in the field of optical packaging of biochips. This paper proposes a novel laser welding method that enhances the joint strength between aluminum nitride (AlN) ceramic and polycarbonate (PC) by laser surface microtexturing. The study investigates the influence of welding methods and microtextures on welding effectiveness, elucidating the bonding mechanisms of the joints. The obtained results showed that dual wavelength laser welding effectively achieves the connection between AlN ceramic and PC. Laser microtexturing increases surface roughness and contact area, leading to stronger mechanical interlocking and overall joint strength. The highest shear strength reached up to 14.66 MPa with longitudinal grooves microtexture. The laser microtexturing improves the hydrophilicity of the AlN surface, facilitating more effective bonding between the materials. The bonding mechanisms at the joint interface include both mechanical interlocking and chemical bonding. Microtexturing improves the stress distribution at the joint interface. The formation of C-O-Al chemical bonds at the interface effectively enhances the joint strength. Longitudinal grooves microtexture exhibit a higher substrate fracture rate due to stress concentration and capillary pores. In contrast, staggered square holes microtexture provide superior mechanical performance through uniform stress distribution and robust mechanical interlocking.