Microsystem Technologies

, Volume 19, Issue 6, pp 783–790 | Cite as

Electrodeposition of copper into high aspect ratio PCB micro-via using megasonic agitation

  • S. Costello
  • N. Strusevich
  • D. Flynn
  • R. W. Kay
  • M. K. Patel
  • C. Bailey
  • D. Price
  • M. Bennet
  • A. C. Jones
  • M. P. Y. Desmulliez
Technical Paper

Abstract

This paper presents the use of micro-particle imaging velocimetry (micro-PIV) to analyse fluid flow and hence ion replenishment in PCB micro-via during the electroplating process. The cross section of a PCB via is fabricated in PMMA to allow optical access to the sample. Fluid flow within two 1:1 aspect ratio blind micro-vias, one with straight side walls and the other with tapered side walls were compared. Flow is also analysed in a 1:1 aspect ratio through via. Flow rates measured using micro-PIV are used to validate simulated flow models. The results show that there are increased flow rates within the blind via with tapered side walls. This goes some way to explaining the improved electroplating results obtained in industry when tapered vias are used. Initial experimental results using megasonic streaming to remove bubbles from blind micro-via and promote ion transportation within high aspect ratio PCB micro-via to enhance electrodeposition are also reported.

References

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Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • S. Costello
    • 1
  • N. Strusevich
    • 2
  • D. Flynn
    • 1
  • R. W. Kay
    • 1
  • M. K. Patel
    • 2
  • C. Bailey
    • 2
  • D. Price
    • 3
  • M. Bennet
    • 4
  • A. C. Jones
    • 4
  • M. P. Y. Desmulliez
    • 1
  1. 1.MicroSystems Engineering Centre (MISEC), School of Engineering and Physical SciencesHeriot-Watt UniversityEdinburghUK
  2. 2.School of Computing and Mathematical SciencesUniversity of Greenwich, Old Royal Naval CollegeLondonUK
  3. 3.Merlin Circuit Technology Ltd., Hawarden Industrial ParkDeesideUK
  4. 4.School of ChemistryUniversity of EdinburghEdinburghUK

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