Modelling of microvia drilling with a Nd : YAG laser

    Authors

    C. Zhang; I. A. Salama; N. R. Quick;A. Kar

    Comments

    Authors: contact us about adding a copy of your work at STARS@ucf.edu

    Abbreviated Journal Title

    J. Phys. D-Appl. Phys.

    Keywords

    OVERHEATED METASTABLE STATES; RADIATION; HOLES; VAPORIZATION; CERAMICS; POLYMERS; Physics, Applied

    Abstract

    Drilling of microvias with Nd:YAG laser of wavelength 1.06 mu m is studied for polymer materials used in high density electronic packaging applications. Generally thermal ablation is the dominant mechanism for such polymer materials in the nanosecond and microsecond laser pulse regimes. A transient thermal model is developed to describe the drilling process. Since a fraction of the laser energy is absorbed inside the polymer layer, volumetric heating occurs and an overheated small metastable region can form inside the layer. Thus the drilling mechanism involves thermal phase change, chemical decomposition and possibly explosion due to rapid thermal expansion and vaporization inside the polymer material. The volumetric heating can cause large thermal stresses inside the material, resulting in convex forms at the free surface of the substrate. Experimental results show the formation of such convex surfaces during laser irradiation. These surfaces eventually rupture and the material is removed explosively due to high internal pressures.

    Journal Title

    Journal of Physics D-Applied Physics

    Volume

    39

    Issue/Number

    17

    Publication Date

    1-1-2006

    Document Type

    Article

    Language

    English

    First Page

    3910

    Last Page

    3918

    WOS Identifier

    WOS:000239991000031

    ISSN

    0022-3727

    Share

    COinS