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Method for Drilling Holes in Ceramic Greensheets Using Pulsed Laser

IP.com Disclosure Number: IPCOM000036861D
Original Publication Date: 1989-Nov-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Manner, HM: AUTHOR [+4]

Abstract

Disclosed is a process that, with suitable optics to focus a beam from a Nd-YAG laser WITHIN a target greensheet formed from a mixture of ceramic particles held together with a polymer binder, small holes can be drilled with the required degree of taper, skewness, and uniformity.

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This is the abbreviated version, containing approximately 100% of the total text.

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Method for Drilling Holes in Ceramic Greensheets Using Pulsed Laser

Disclosed is a process that, with suitable optics to focus a beam from a Nd- YAG laser WITHIN a target greensheet formed from a mixture of ceramic particles held together with a polymer binder, small holes can be drilled with the required degree of taper, skewness, and uniformity.

While laser drilling of holes in ceramic greensheets has been demonstrated
[*], drilling of holes with diameters less than 0.0035" with minimum taper and high density remains a formidable problem.

The standard method of laser drilling of holes uses a laser focussed onto the surface of the workpiece. It has been discovered, however, that the mechanism governing the drilling of ceramic greensheets with a Nd-YAG laser is different from that found in the normal metal drilling case, and that light from the laser (using an f/3 optical system) must be focussed to a point within the greensheet.

Hole patterns of 10,000 holes per sheet with diameters 0.0035" and wall angles less than 2 degrees have been drilled using such an optical system.

Reference: M. Allmen, "Laser Drilling Velocity in Metals," J. App. Phys. 47, 5460 (1976).

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