Revisit of wirebonding on immersion silver-finish board

Y. M. Cheung, Siu Wing Or, Albert Sze

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

5 Citations (Scopus)


In this article, we evaluated the bondability of aluminum and gold wires on multilayer FR-4 printed circuit board (PCB) with immersion silver finish by using an automatic wedge bonder equipped with ultrasonic transducers operating at conventional 62 kHz and at higher frequency of 138 kHz. Very good bondability of aluminum was obtained at both bonding frequencies. However, the bonder with transducer at higher frequency provided a larger window for setting the bond power. Its bond points exhibit a smaller deformation of the bonding wire, less heel crack and less metal splash. Tarnishing of the silver finish was observed if the boards were left in atmosphere for days. The XPS analysis revealed an additional layer of sulfur compound on the silver surface. The adverse effect of this layer made the wirebonding very difficult and proper storage of the board was important to maintain good bondability.
Original languageEnglish
Title of host publicationInternational Symposium on Electronic Materials and Packaging, EMAP 2000
Number of pages5
ISBN (Electronic)0780366549, 9780780366541
Publication statusPublished - 1 Jan 2000
Externally publishedYes
EventInternational Symposium on Electronic Materials and Packaging, EMAP 2000 - Hong Kong, Hong Kong
Duration: 30 Nov 20002 Dec 2000


ConferenceInternational Symposium on Electronic Materials and Packaging, EMAP 2000
Country/TerritoryHong Kong
CityHong Kong

ASJC Scopus subject areas

  • General Engineering


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