Title

Modelling Of Microvia Drilling With A Nd : Yyyag Laser

Abstract

Drilling of microvias with Nd : YAG laser of wavelength 1.06 νm 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. © 2006 IOP Publishing Ltd.

Publication Date

9-7-2006

Publication Title

Journal of Physics D: Applied Physics

Volume

39

Issue

17

Number of Pages

3910-3918

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1088/0022-3727/39/17/030

Socpus ID

33747584655 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/33747584655

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