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The characteristics and formation mechanism of V‐shaped groove formed by laser‐activated metallization of aluminum nitride (AlN) ceramic under different shielding gas environments of air, nitrogen, and argon are investigated, using a novel analysis way which is based on the intensity distribution of the focused laser beam. It is found that the width of the V‐shaped groove is slightly different under different gas environments, and the depth of the V‐shaped groove is nearly the same, which means that the energy thresholds required for laser decomposition of AlN ceramic are different in various gas environments: air > nitrogen > argon, and the energy required for laser etching AlN ceramic is the same. It is also found that the nonlinearity in the curves of depth and width versus different machining parameters, which are explained in detail. [ABSTRACT FROM AUTHOR]

Laser activation is an efficient metallization method for producing conductive paths on Aluminum Nitride (AlN) ceramic surface. The problem is that the precipitated aluminum on AlN ceramic is sensitive to laser energy density. The fluence range of laser pulses is the most important parameter to control the activation quality of AlN ceramic. However, It is still very difficult to obtain an accurate value of this parameter, due to the non-uniform intensity distribution of the laser focal spot. Then, a new evaluation method is introduced, by accurately calculating the intensity distribution of the focal spot and changing the scanning velocity. The fluence range of laser pulses is evaluated as 21.53J/(cm^2)~26.02J/(cm^2) for laser activation through the verification experiments. It is also found that the roughness of the flattop laser beam for AlN ceramic should be controlled within ±9.44% when a flattop beam is available. [ABSTRACT FROM AUTHOR]

Aluminum nitride ceramics has excellent thermal conductivity and insulation property, making it a kind of excellent electronic packaging material. But enhancing the bonding strength between the metal layer and aluminum nitride (AlN) ceramic is a challenging problem. Especially regarding the lack of accurate data analysis on the stress between interfaces, enhancing adhesive strength still relies on blind attempts. By using the finite element method, this study reveals that the shear stress generated between the metal/ceramic interface is concentrated at the interface edge. Based on this finding, a method of inserting micro-pore arrays at the edge is proposed to enhance the interfacial bonding strength. The simulation results show that by inserting micro-pores with an appropriate density, the interface shear stress between metal and ceramic can be reduced obviously by 36 %. Finally, vertical peel-off verification experiments were designed. After inserting micro-pores to the interface, the bonding strength of the interface increased from 8.75 MPa to 11.69 MPa, and the performance was improved by 33.6 %. The experimental results were consist with the simulation results and indicated that the micro-pores had a significant effect on improving the bonding strength. • A method is proposed to insert micropores at the edge of the AlN interface to enhance the interface bonding strength. [ABSTRACT FROM AUTHOR]