Diagnostic wire bond pull tester
US5591920A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 17, 1995 |
| Grant date | Jan 7, 1997 |
| Priority date | — |
| Expiry date | Nov 17, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/19043
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A novel pull strength tester is incorporated into an automatic wire bonder for performing pull strength tests during production bonding operation. The pull strength tester is provided with a control for automatically applying increments of pull force on a fine wire after making a bond. The control senses the elongation of the fine wire as a result of the force applied and is capable of terminating the pull test at a predetermined threshold value or continuing to increase the force until a break occurs. After each increase in force, a continuity circuit determines if the wire has broken at the bond or the bond has lifted off the bonding target. The system employs the information to determine if a proper bond was made and/or if a short tail was made which could affect the subsequent attempt to form a proper ball for a subsequent first bond.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.