LASER DRILLING OF Al2O3
Original Publication Date: 1985-Sep-01
Included in the Prior Art Database: 2005-Feb-19
The present method uses an excimer laser to rapidly drill precision holes through pre-shrunk Al2O3 substrates for making contact through the substrate. The holes are drilled prior to deposition of a film on the substrate. A precision X-Y motor-driven stage is used to move the Al2O3 substrate with respect to the laser beam. The present method is more efficient and cost effective than the prior-art method which employed diamond drills. Using the present method, an excimer laser at a fluence of 140 mJ/cm2 per pulse at 248 nm wavelength was focused through a 15 cm lens onto a 0.025 inch thick slab of 99.5% Al2O3 . At a rate of 25 pulses per second, a hole 1 mm in diameter was drilled in approximately 1.5 minutes.