RF circuit integration using high Q copper inductors on organic substrate and solder-bumped flip chip technology

Guo Wei Xiao, Xiao Huo, Philip Ching Ho Chan

Research output: Journal article publicationConference articleAcademic researchpeer-review

3 Citations (Scopus)


In this paper, high Q copper inductors were fabricated by the electroplating process on low-cost and low-loss BT and glass substrates. The RF circuit chips were assembled on the BT and glass substrates with copper spiral inductors using solder-bumped flip-chip and MCM technology. Eutectic Sn/Pb solder bumps were fabricated on the bonding pads with the electroless Ni/Au under-bump metallurgy (UBM) layers. This technique achieved the miniaturization of whole RF block and reduced the loss of substrate and the power consumption. The inductors exhibited Q-factors as high as 25 at 2.4GHz. The performance of RF circuits assembled on various substrates were compared and analyzed. In comparison with the VCO with on-chip Al inductor, the circuit with copper inductor on BT substrate had a phase noise of - 108dBc/Hz at 600kHz offset from a 2.4-GHz carrier. It was observed that there was almost no substrate loss for inductors on BT and glass substrates. Finally, the effect of fabrication defects and solder joint resistance were also investigated.
Original languageEnglish
Pages (from-to)487-492
Number of pages6
JournalProceedings - Electronic Components and Technology Conference
Publication statusPublished - 17 Jul 2003
Externally publishedYes
Event53rd Electronic Components and Technology Conference 2003 - New Orleans LA, United States
Duration: 27 May 200330 May 2003

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

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