Pulse CO(2) laser drilling of green alumina ceramic

Ceramics are used as thermal conductors and electrical insulators in integrated circuit packaging. We have investigated TEA CO(2) laser drilling of green alumina ceramic sheets consisting predominantly of alumina with approximately 10% PVB (polyvinyl butyral) as the polymer binder. Experiments with 9.5 and 10.6 mum wavelengths show that the holes made with a 9.5 mum CO(2) laser beam, where a larger percentage of the total laser energy is deposited directly into the polymer binder, are smaller, more straight-sided and cleaner