Patent · US Expired

Packaged semiconductor device with test circuits for determining fabrication parameters

US4970454A · kind A · utility

72Cited by
12References
17Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 15, 1990
Grant dateNov 13, 1990
Priority date
Expiry dateMar 15, 2010

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01L2924/3011
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A test circuit (40) fabricated in an integrated circuit and connected to an I/O pin (36) of the packaged device (32) for providing information indicative of substrate process parameters. The test circuit (40) comprises a test transistor (24) connected to a pin (36) of the packaged device (32), and an isolation circuit (52) responsive to a signal on an input test terminal (48) for activating the test transistor (24). The isolation circuit (52) is responsive to the absence of the test signal for isolating the test transistor (24) from the pin (36), and thus isolating it from other functional circuitry (54) of the integrated circuit which is also connected to the pin (36).

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