Abstract: A theoretical model was
developed to describe blind hole profiles in Nd: YAG laser
drilling. In most cases, the drilled holes resemble a
spindle-like shape as is predicted by the theoretical model.
Derived from the model, an interesting and useful phenomenon:
the so-called tunnelling effect, by which cylindrical holes with
minimal tapering together with a relatively small heat affected
zone can be achieved. The mechanism and the drilling conditions
to realize the tunnelling effect are analyzed and experimental
evidences are provided.
Key words:
Laser Drilling Profile
Manuscript received on
November 15, 1995; revised manuscript February 1, 1996
|