Composite semiconductor unit and method

US4038677A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Karl Nagel · Gomaringen, DE
• Gerhard Conzelmann · Echterdingen, DE
• Horst Gschwendtner

Key dates

• Filing date: Feb 7, 1975
• Grant date: Jul 26, 1977
• Expiry date: Feb 7, 1995

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L2924/0002
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

To detect defective elements in a composite semiconductor unit, such as a plurality of transistors, diodes, or the like, connected together to provide desired output levels, the elements are arranged in the unit, for example by providing coupling resistors, or melt positions in the connections to the respective units so that defective elements in the unit can be recognized and isolated from the remaining, non-defective elements in the unit, so that, overall, a semiconductor unit results which is operative and from which defective sub-elements have been, electrically, removed. The defective elements are recognized by applying a voltage to an electrode pair which is below the normal breakdown voltage between the pair of electrodes, then determining the total blocked current flow to the unit and, if the blocked current flow is not at design level, individually measuring the electrical characteristics of the elements until the defective element is identified, whereupon a current pulse is applied thereto in order to electrically isolate the specific element from the unit.