AlN ceramics are considered as the most ideal substrate material for high integration and high-power devices packaging due to its high thermal conductivity

low thermal expansion coefficient and good mechanical strength

and have great prospects for application in automotive chips

aerospace and defense military. However

as the primary methods of the substrate planarization

lapping and polishing of AlN ceramics are encountering the bottleneck of low processing efficiency caused by the employment of loose abrasive slurries. In addition

the chemicals in abrasive slurries can cause increased environmental expenses. In this research

for the purpose of solving environmental problems and improving the polishing efficiency of AlN ceramics

a vitrified-bonded abrasive pellet containing fine abrasives is employed to realize the fixed-abrasive dry polishing. With this method

higher material removal rate can be obtained

but the chip cannot be discharged in time during the dry machining

which will lead to the deterioration of surface integrity. Consequently

an elliptic ultrasonic vibration is applied to the abrasive pellet during the dry polishing. It is found from experiments that the elliptic ultrasonic vibration has a catalytic effect on the chip emission

which is more favourable for better surface quality and higher material removal rate.