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Full-Text Articles in Mechanical Engineering
Thermal Modeling And Laser Beam Shaping For Microvias Drilling In High Density Packaging, Chong Zhang
Thermal Modeling And Laser Beam Shaping For Microvias Drilling In High Density Packaging, Chong Zhang
Electronic Theses and Dissertations
Laser drilling of microvias for organic packaging applications is studied in present research. Thermal model is essential to understand the laser-materials interactions and to control laser drilling of blind micro holes through polymeric dielectrics in multilayer electronic substrates. In order to understand the profile of the drilling front irradiated with different laser beam profiles, a transient heat conduction model including vaporization parameters is constructed. The absorption length in the dielectric is also considered in this model. Therefore, the volumetric heating source criteria are applied in the model and the equations are solved analytically. The microvia drilling speed, temperature distribution in …
Annular Beam Shaping And Optical Trepanning, Danyong Zeng
Annular Beam Shaping And Optical Trepanning, Danyong Zeng
Electronic Theses and Dissertations
Percussion drilling and trepanning are two laser drilling methods. Percussion drilling is accomplished by focusing the laser beam to approximately the required diameter of the hole, exposing the material to one or a series of laser pulses at the same spot to melt and vaporize the material. Drilling by trepanning involves cutting a hole by rotating a laser beam with an optical element or an xy galvo-scanner. Optical trepanning is a new laser drilling method using an annular beam. The annular beams allow numerous irradiance profiles to supply laser energy to the workpiece and thus provide more flexibility in affecting …