Patent ID: 6864459

Claim:
A method of drilling a hole in a material, said hole to have a final diameter, wherein said material has a back side and a second material is located at said back side, comprising: the steps of: generating a first laser beam and generating a second laser beam, said step of generating a first laser beam comprising generating a first high power percussive laser beam that has greater power than said second laser beam, said first high power percussive laser beam producing a first level of power and said first high power percussive laser beam being focused to a first high power percussive laser beam spot diameter that is slightly smaller than said final diameter of said hole, directing said first high power percussive laser beam at said material to remove the bulk of said material to form a ragged hole having a diameter slightly smaller than said final diameter of said hole, said step of directing said first high power percussive laser beam at said material to remove the bulk of said material to form a ragged hole being accomplished by using said first high power percussive laser beam spot diameter to directly form said ragged hole without trepanning, said step of directing said first high power percussive laser beam at said material to remove the bulk of said material to form a ragged hole being stopped before said ragged hole reaches said back side and before said ragged hole reaches said second material thereby leaving a thin membrane of said material between said ragged hole and said second material, said step of generating a second laser beam comprising generating a second and trepanning laser beam that has less power than said first laser beam, said second and trepanning laser beam producing a second level of power that is less than said first level of power and said second and trepanning laser beam having a spot diameter substantially smaller than said diameter of said hole, and directing and trepanning by tracing said second and trepanning laser beam along said diameter and at said hole being formed for expanding said ragged hole having a diameter slightly smaller than said final diameter of said hole so that said hole is at said final diameter and for accurately cleaning up said ragged hole so that said final hole has said final diameter and has dimensions of high precision and directing and trepanning said second and trepanning laser beam through said thin membrane of said material so that said final hole extends to said second material.