Abstract
In order to ensure that the laser remains at the forefront of micro-via forming in the future, many new laser technologies are being investigated by PCB manufacturers for high-density interconnect (HDI) printed circuit boards. As there were limitations of etching small micro-via size and registration in conformal masked laser drilling method, copper direct drilling by laser irradiation has been developed as an alternative. This research work was studied on the difference between several surface treatment processes for enhancing the laser absorptivity of copper, and reducing the thickness of the copper layer by chemical means in laser drilling technology. Also, the effect of critical laser drilling parameters and dielectric material properties were studied in this paper. It was shown that unreinforced and pure resin epoxy material was better in laser ablated microvia maufacturing. The laser absorptivity of copper and copper thickness were very critical factors for implementing copper direct laser drilling technology sucessfully in printed circuit board industry. By using same laser energy, better hole size and shape was achieved by oxide replacement process (Multibond) which showed higher surface roughness Ra, 0.5606um and grain structure among the oxide surface treatments in this study. It was found that 5-7μm copper thickness was more suitable and achievable for controlling micro-via hole size and shape in CO2 copper direct laser drilling.
Original language | English |
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Title of host publication | PICALO 2004 - 1st Pacific International Conference on Applications of Laser and Optics, Conference Proceedings |
Pages | 1-6 |
Number of pages | 6 |
Publication status | Published - 1 Dec 2004 |
Event | PICALO 2004 - 1st Pacific International Conference on Applications of Laser and Optics - Melbourne, VIC, Australia Duration: 19 Apr 2004 → 21 Apr 2004 |
Conference
Conference | PICALO 2004 - 1st Pacific International Conference on Applications of Laser and Optics |
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Country/Territory | Australia |
City | Melbourne, VIC |
Period | 19/04/04 → 21/04/04 |
ASJC Scopus subject areas
- Geochemistry and Petrology
- Electrical and Electronic Engineering