Method and apparatus for drilling microvia holes in electrical circuit interconnection packages
AssigneesExcellon Automation, Exitech Limited
InventorsMalcolm Charles Gower, Philip Thomas Rumsby, Dafydd Wyn Thomas
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Abstract
This invention relates to using mid-infrared high-power pulsed laser radiation sources for drilling high-quality microvia interconnection holes in printed circuit (wiring) boards and other electrical circuit packages.
Claims52
A method of drilling a microvia hole in an electrical circuit interconnection package which is a laminate of at least one metal layer and at least one dielectric layer, said method comprising the steps of:
- providing a pulsed laser radiation source emitting radiation having a wavelength in the mid-infrared range, wherein said wavelength is longer than 3 μm and shorter than 8 μm;
- and
- focusing said radiation on the electrical circuit interconnection package at a location where the microvia hole is to be formed.
A laser drilling tool for drilling a microvia hole in a printed circuit board which is a laminate of at least one conductive layer and at least one dielectric layer, said tool comprises a pulsed laser radiation source emitting radiation in the infrared wavelength range, wherein said wavelength is longer than 3 μm and shorter than 8 μm.
A method of drilling a microvia hole in a printed circuit board having a copper layer laminated on top a dielectric layer, said method comprising the steps of:
- emitting laser radiation from a pulsed laser radiation source, said laser radiation having a wavelength of from about 1.5 μm to about 5 μm;
- and
- focusing said radiation on the copper layer of the printed circuit board at a location where the microvia hole is to be drilled;
- wherein the pulsed laser radiation source has an irradiation fluence of greater than 10 J/cm2.
Dependencies are inferred from the claim text.