Browse Prior Art Database

Laser Drilled Holes in Vitreous Carbon

IP.com Disclosure Number: IPCOM000080694D
Original Publication Date: 1974-Jan-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Lorenz, MR: AUTHOR [+2]

Abstract

It is often required that fine holes be drilled in different materials for fluid flow applications. These include holes for nozzle applications, as well as mist or spray applications. Lasers are often used for such drilling. Generally, laser drilling results in a certain amount of cratering due to the fact that there is a molten material present, because of the finite range between the melting point and evaporation point of the material in which the hole is being drilled.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 84% of the total text.

Page 1 of 1

Laser Drilled Holes in Vitreous Carbon

It is often required that fine holes be drilled in different materials for fluid flow applications. These include holes for nozzle applications, as well as mist or spray applications. Lasers are often used for such drilling. Generally, laser drilling results in a certain amount of cratering due to the fact that there is a molten material present, because of the finite range between the melting point and evaporation point of the material in which the hole is being drilled.

The cratering effect can be eliminated and very fine precise non-cratered holes achieved, by utilizing materials having a melting and boiling point substantially concurrent, or materials that sublime or materials that form gaseous products on reaction with the atmosphere at elevated temperatures. It has been found that vitreous carbon has one of the characteristics. By rotating the vitreous carbon while drilling, for example, with a Q-switched YAG laser, a very smooth cylindrical hole is generated, and the diameter of the hole is determined by the position of the laser beam relative to the center of rotation of the vitreous carbon. By this technique, smooth holes may be drilled in vitreous carbon. Holes as fine as 0.001 inch may be made with smooth walls (as viewed under a scanning electron microscope).

By this technique, holes may be also drilled in normal graphite and pyrolytic carbon, but the walls of the holes drilled in these two materials are not as s...