Patent · US Expired

Missing wire detector

US4786860A · kind A · utility

12Cited by
5References
16Claims
0Family size

Assignee

Inventor

Key dates

Filing dateApr 8, 1987
Grant dateNov 22, 1988
Priority date
Expiry dateApr 8, 2007

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01L2924/3011
  • WIPO fieldSemiconductors
  • WIPO sectorElectrical engineering

Abstract

The absence of a wire (40) in proper position under the bonding tool (32) of an ultrasonic wire bonder is detected by energizing the bonder transducer (14) while the wire is pulled to break it after the second bond (B) has been made. The pulling of the wire to break it changes the transducer impedance, which is monitored to signal presence or absence of a wire in its proper location.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.