Method for drilling subminiature through holes in a sensor substrate with a laser
AssigneeSenDex Medical, Inc.
InventorsMatthew J. Leader, Jeffrey Graves, John M. Moorman
Life of this patent
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Abstract
The present invention is a method for drilling a subminiature through hole through a substrate. The through holes of the present invention are preferably drilled through an alumina substrate which is essentially impervious to aqueous electrolytes and blood over long periods of storage in potentially reactive environments. The holes are drilled by directing a sealed type CO.sub.2 laser at a predetermined position located on the substrate, energizing the laser at a power of approximately 75 to 225 watts, such that the laser beam focuses on the substrate at the predetermined position, and treating the substrate after the laser has drilled the hole.
Claims25
A method for drilling subminiature through holes through a substrate of a sensor assembly, including the steps of:
- providing a polycrystalline ceramic substrate capable of withstanding a of 6 to 9 for a period of at least a week;
- providing a laser;
- energizing the laser and generating a laser beam;
- energizing the laser such that the laser beam focuses at a predetermined position located on the substrate until a through hole is formed;
- and
- annealing the substrate at a sufficient temperature and duration to oxidize and crystallize the surface area of the hole.
A method for drilling subminiature through holes through a substrate of a sensor assembly, including the steps of:
- providing a polycrystalline ceramic substrate capable of withstanding a pH of 6 to 9 for a period of at least a week;
- coating the substrate with a water soluble coating;
- providing a CO.sub.2 laser;
- energizing the laser and generating a laser beam;
- positioning the laser such that the laser beam focuses at a predetermined position located on the substrate and operating the laser at an energy level sufficient that a through hole is formed;
- and
- annealing the substrate at a temperature in the range of 1000.degree.-1400.degree. C. for a sufficient duration to oxidize and crystallize the surface area of the hole.
A method for drilling subminiature through holes through a substrate of a sensor assembly, including the steps of:
- providing an alumina substrate having a thickness that is approximately 0.025 to approximately 0.040 inches in thickness;
- coating the substrate with a water soluble coating;
- providing a closed CO.sub.2 laser;
- energizing the laser and generating a laser beam;
- forming a through hole in the substrate by the further steps of positioning the laser such that the laser beam focuses at a predetermined position located on the substrate and operating the laser wherein the laser is a pulsed in a range of 200 to 1000 Hz with a pulse length in the range of approximately 38 to 400 .mu.sec. and a total duration of in the range of approximately 0.25 to 0.50 seconds per hole to thereby form a through hole that is approximately 0.002 to approximately 0.006 inches in diameter;
- and
- annealing the substrate at a temperature in the range of 1000.degree.-1400.degree. C. for a sufficient duration to oxidize and crystallize the surface area of the hole.
Dependencies are inferred from the claim text.