Aluminium nitride (AlN) ceramic offers a high dielectric constant, excellent thermal conductivity, high volume resistivity, robust mechanical properties, chemical inertness, and high temperature resistance. Its thermal expansion coefficient matches silicon, making it ideal for microelectronics substrates and electronic packaging. As the semiconductor industry advances and devices miniaturise, precise machining of AlN becomes crucial. However, AlN's high hardness and brittleness make it difficult to machine using conventional techniques like diamond sawing, milling, and grinding, which often result in tool wear, cracks, and inaccuracies. Ultrashort pulsed lasers have emerged as a flexible solution, offering benefits such as no tool wear, minimal thermal damage, no cracking, and high efficiency. These lasers have been successfully used for machining materials like silicon nitride and alumina.

While most literature focuses on ultrashort pulsed lasers with average powers below 50 W, picosecond lasers with up to 300 W are now available, offering advantages like burst mode for energy discretisation and higher frequencies with lower pulse energies. The demand for high throughput applications has driven advancements in ultrashort pulsed lasers, making it essential to explore their use in machining advanced technical ceramics like AlN.

This study uses a 300 W picosecond laser system at 1064 nm to investigate process parameters' influence on material removal rate, cutting speed, heat-affected zone, and surface oxidation. Material removal mechanisms and productivity-enhancing conditions, including hybrid methods like laser scribing with mechanical breakage, are explored. Finally, optimised parameters are used to demonstrate high-quality, high-throughput cutting of aluminium nitride.