Patent US4586642A successfully refreshed from Google Patents.
US4586642A
Expired / Lapsed
US
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Wire bond monitoring system
Assignee: Kulicke and Soffa Investments Inc
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Filing: 1985-05-13
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Granted: 1986-05-06
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Expires: 2005-05-13
Abstract
Abstract Apparatus is provided for monitoring conditions of a fine wire interconnection during a bonding operation. The apparatus comprise a system which is capable of being installed on new automatic wire bonders or retrofitted into existing automatic wire bonders of the type which employ a main bonding processor for controlling the motion of the bonding tool. The semiconductor to be bonded is connected to a reference voltage and a variable frequency oscillator is magnetically or a.c. coupled to the fine wire above the bonding tool and below the wire feed. The bonding wire incurs changes in inductive and capacitive reactance during the bonding operation which cause variations in the frequency of the oscillator. A series of frequency samples are taken and recorded during a teaching operation in which good wire bond interconnections are made. The recorded frequency samples for each fine wire interconnection are compared to the frequency samples being taken during subsequent bonding operations and decisions are made at critical points of the bonding operation whether or not a good wire bond interconnection is being made without damaging the semiconductor device with excessive force or current.
Inventors
- 👤 John D. Dreibelbis
- 👤 I. Marvin Weilerstein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:42
CPC Classifications
B; B23; B23K; B23K20/00; B23K20/002; B23K20/004; B23K20/005; B23K20/007; H; H10; H10W; H10W72/00; H10W72/071; H10W72/0711; H10W72/07141; H10W72/075; H10W72/07502; H10W72/07521; H10W72/07531; H10W72/07532; H10W72/07533; H10W72/50; H10W72/531; H10W72/536; H10W72/5363; H10W72/551; H10W72/552; H10W72/5522; H10W72/5524; H10W72/90; H10W72/931; H10W72/932; H10W90/00; H10W90/701; H10W90/751; H10W90/756
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
289 words
A system for monitoring conditions of a fine wire bond interconnection as it is being made between a semiconductor device terminal and a lead out pad, comprising; an automatic wire bonder of the type having a fine wire to be bonded extending through a wire guide of a bonding tool and the motion of said bonding tool being controlled by a bonding processor, a reference voltage connection on said semiconductor device to be bonded, a variable frequency oscillator coupled to said fine wire to be bonded, said oscillator frequency being varied by the changes in inductive and capacitive reactance in said fine wire as it is bonded to said semiconductor device and then to said lead out pad, sensing means coupled to said oscillator for providing digital data outputs proportional to said changes in frequency of said variable frequency oscillator, detector means coupled to said sensing means for processing and storing said digital data outputs from said sensing means, memory means in said bonding processor for storing a plurality of digital data outputs from said detector means representative of the frequency of said variable frequency oscillator at different times in a bonding operation for each of the fine wire bond interconnections to be made on a semiconductor device, comparison means in said bonding processor for comparing said digital data outputs from said detector means with the digital data stored in said memory means for determining if the fine wire bond interconnection being made by said automatic wire bonder conforms to the desired frequency digital data representation of good wire bond interconnections, and display means coupled to said bonding processor for indicating predetermined deviations from said digital data stored in said memory means representative of good fine wire bond interconnections.
Claim 2
Independent Claim
289 words
A system for monitoring conditions of a fine wire bond interconnection as it is being made between a semiconductor device terminal and a lead out pad, comprising; an automatic wire bonder of the type having a fine wire to be bonded extending through a wire guide of a bonding tool and the motion of said bonding tool being controlled by a bonding processor, a reference voltage connection on said semiconductor device to be bonded, a variable frequency oscillator coupled to said fine wire to be bonded, said oscillator frequency being varied by the changes in inductive and capacitive reactance in said fine wire as it is bonded to said semiconductor device and then to said lead out pad, sensing means coupled to said oscillator for providing digital data outputs proportional to said changes in frequency of said variable frequency oscillator, detector means coupled to said sensing means for processing and storing said digital data outputs from said sensing means, memory means in said bonding processor for storing a plurality of digital data outputs from said detector means representative of the frequency of said variable frequency oscillator at different times in a bonding operation for each of the fine wire bond interconnections to be made on a semiconductor device, comparison means in said bonding processor for comparing said digital data outputs from said detector means with the digital data stored in said memory means for determining if the fine wire bond interconnection being made by said automatic wire bonder conforms to the desired frequency digital data representation of good wire bond interconnections, and display means coupled to said bonding processor for indicating predetermined deviations from said digital data stored in said memory means representative of good fine wire bond interconnections.
Claim 3
Dependent Claim
33 words
A system for monitoring conditions of a fine wire bond interconnection as set forth in claim 1 which further includes a miniature transformer for coupling said variable frequency oscillator to said fine wire.
Claim 4
Dependent Claim
45 words
A system for monitoring conditions of a fine wire bond interconnection as set forth in claim 2 wherein said miniature transformer comprises a toroidal core and said fine wire extends through the central aperture of said toroidal core to provide a single turn secondary winding.
Claim 5
Dependent Claim
39 words
A system for monitoring conditions of a fine wire bond interconnection as set forth in claim 3 wherein said variable frequency oscillator comprises a plurality of turns on said toroidal core to provide a primary winding of said transformer.
Claim 6
Dependent Claim
47 words
A system for monitoring conditions of a fine wire bond interconnection as set forth in claim 1 wherein said sensing means comprises a counter coupled to said variable frequency oscillator, said oscillator being timed to count the output from said oscillator for a predetermined length of time.
Claim 7
Dependent Claim
42 words
A system for monitoring conditions of a fine wire bond interconnection as set forth in claim 5 wherein said detector means includes control means for determining if said fine wire is in contact with said reference voltage connection on said semiconductor device.
Claim 8
Dependent Claim
57 words
A system for monitoring conditions of a fine wire bond interconnection as set forth in claim 5 wherein said bonding processor is programmed to continuously update said stored digital data representative of the frequency of said fine wire while said fine wire is suspended in free air before contacting said reference voltage connection on said semiconductor device.
Claim 9
Dependent Claim
32 words
A system for monitoring conditions of a fine wire bond interconnection as set forth in claim 7 wherein said detector means is provided as part of the logic of said bonding processor.
Claim 10
Dependent Claim
29 words
A system for monitoring conditions of a fine wire bond interconnection as set forth in claim 1 wherein said variable frequency oscillator is capacitively coupled to said fine wire.
Claim 11
Dependent Claim
43 words
A system for monitoring conditions of a fine wire bond interconnection as set forth in claim 9 which further includes a wire feed for supplying said fine wire and said wire feed is insulated from said reference voltage connection on said semiconductor device.
Claim 12
Dependent Claim
33 words
A system for monitoring conditions of a fine wire bond interconnection as set forth in claim 1 wherein the peak to peak voltage in said fine wire is maintained below approximately 150 millivolts.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-05-05 | 1989-11-04 | 1990-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-05 | 1993-11-04 | 1994-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-05 | 1997-11-04 | 1998-05-06 | $7700.00 | Window Closed / Lapsed |