Description

With the quest for ever shrinking dimensions in packaging, display, semiconductor and medical device industries, the resolution capabilities of direct laser ablation with Excimers lasers get traction and interest from these industries. The short UV wavelengths of Excimer lasers impose inherent advantages with respect to imaging technologies and their respective reachable resolution on substrate which are unmatched by other laser technologies. Direct ablation down to 1µm lateral lines and spaces resolution are possible and being used in industry for quite some years.

Reachable resolutions depend not only on the wavelength of the light source but as well from the material being processed and other side effects as well. With an increase in aspect ratio issues like overetching and resessing the surface become dominant resolution limiters and methods of maintaining the high optical resolution rely mainly on altering the material itself.

A coating on top of the substrate that is easily applied and even more easily removed after the process may act as good protection layer. Facilitating easy cleaning of the substrates and protecting the substrates surface from the harsh microenvironments of ablative processes is likely the dominant motivation for such coatings. If the coating shows an adjusted UV absorption, it might act as well for improving the process resolution.

Initial results that point into this direction will be shown.

Within the variety of excimer applications three representative ones have been chosen to explore the benefits and drawbacks of water washable protective coatings: a) drilling of nozzles in polyimide films; b) structuring of electronics packaging materials and c) drilling of thin metal foils. The materials have been processed with the two main Excimer wavelengths 308 and 248nm using high resolution imaging systems.

Within this publication the results of the experiments will be detailed along with a comparative study using uncoated materials. Results will be discussed as well as costs and benefits analyzed.

Contributing Authors

  • Jan Brune
    Coherent LaserSystems GmbH & Co KG
  • Rainer Pätzel
    Coherent LaserSystems GmbH & Co KG
  • Rolf Senczuk
    Coherent LaserSystems GmbH & Co KG
  • John Moore
    Daetec, LLC
  • Allison Gray
    Daetec, LLC
Jan Brune
Coherent LaserSystems GmbH & Co KG
Track: Laser Materials Microprocessing
Session: On-demand Only
Date/Time:
Location:

Keywords

  • Excimer, Ablation, Imaging, Protective Coating, Water Washable, Dielectric Built Up
  • Wavelenght Matched, Vias, Nozzles, Invar, Packaging, Debris, Burr