Patent CA467765A successfully refreshed from Google Patents.
EP0331891A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Device for laser bonding process control
Assignee: International Business Machines Corp
•
Filing: 1989-01-27
•
Granted: —
•
Expires: 2009-01-27
Abstract
Abstract An optical process monitor primarily for use in laser wire bonding detects the reflectivity change of the wire (12) being bonded in order to provide feedback control of the high power laser (10) used for bonding the wire (12) to a pad (14). The beam of a low power laser (30) which is co-linear or combined with the high power laser beam is conducted to the bond site and reflected from the wire (12) during the bonding cycle. The change in reflectivity of the wire during the bonding cycle is detected from the reflected low power laser beam. A signal commensurate with the detected change of reflectivity is used to control the power or duration of the high power laser (10) during bonding.
Inventors
- 👤 Arunava Gupta
- 👤 Brain W. Hussey
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 14:10
CPC Classifications
B; B23; B23K; B23K26/00; B23K26/02; B23K26/03; B23K26/032; H; H10; H10W; H10W72/00; H10W72/071; H10W72/0711; H10W72/07141; H10W72/07183; H10W72/075; H10W72/07531; H10W72/07535; H10W72/50; H10W72/521; H10W72/522; H10W72/531; H10W72/533; H10W72/534; H10W72/536; H10W72/551; H10W72/552; H10W72/5522; H10W72/5525; H10W72/555; H10W72/59; H10W72/90; H10W72/921; H10W72/923; H10W72/951; H10W72/952; H10W74/00
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
125 words
A device for monitoring the energy dissipated during laser bonding of a metal workpiece (12) to another workpiece (14) comprising: first means (10) for propagating a first beam of energy to the metal workpiece (10) and the other workpiece (14) to be bonded sufficient to bond the metal to the other workpiece; second means (30) for propagating a second beam of energy co-linearly with said first beam, said second beam being reflected from the metal workpiece (10); detection means (48) disposed for detecting the reflected second beam and providing a reflectance signal commensurate with the reflected second beam, and control means (74, 92) coupled to said detection means (48) for receiving said reflectance signal and controlling said first means (10) responsive to said reflectance signal.
Claim 2
Independent Claim
125 words
A device for monitoring the energy dissipated during laser bonding of a metal workpiece (12) to another workpiece (14) comprising: first means (10) for propagating a first beam of energy to the metal workpiece (10) and the other workpiece (14) to be bonded sufficient to bond the metal to the other workpiece; second means (30) for propagating a second beam of energy co-linearly with said first beam, said second beam being reflected from the metal workpiece (10); detection means (48) disposed for detecting the reflected second beam and providing a reflectance signal commensurate with the reflected second beam, and control means (74, 92) coupled to said detection means (48) for receiving said reflectance signal and controlling said first means (10) responsive to said reflectance signal.
Claim 3
Dependent Claim
57 words
A device as set forth in claim 1, wherein said first means (10) is a first laser means for bonding the workpieces (12, 14) and said second means (30) is a second laser means operating at a lower power level than said first laser means and at a wavelength different from that of said first laser means.
Claim 4
Dependent Claim
24 words
A device as set forth in claim 1 or 2, wherein said detection means includes means (44) for spatially separating said reflected second beam.
Claim 5
Dependent Claim
18 words
A device as set forth in claim 3, where said means (44) for spatially separating is optical means.
Claim 6
Dependent Claim
32 words
A device as set forth in claim 3 or 4, wherein said detection means further includes conversion means (48) for converting said spatially separated reflected second beam into an electrical reflectance signal.
Claim 7
Independent Claim
40 words
A device as set forth in at least one of the claims 1 to 5, wherein said first means (10) includes a shutter (11) and said control means controls the time duration of said first beam by controlling said shutter.
Claim 8
Independent Claim
40 words
A device as set forth in at least one of the claims 1 to 5, wherein said first means (10) includes an acousto-optic modulator and said control means controls the power of said first beam by controlling said acousto-optic modulator.
Claim 9
Independent Claim
32 words
A device as set forth in one or more of the claims 1 to 7, wherein said first beam and said second beam pass through a cold mirror for being propagated co-linearly.
Claim 10
Independent Claim
26 words
A device as set forth in one or more of the claims 1 to 8, wherein said second laser means (30) is a visible light laser.
Claim 11
Independent Claim
25 words
A device as set forth in one or more of the claims 1 to 8, wherein said second laser means (30) is a infrared laser.
Claim 12
Independent Claim
30 words
A device as set forth in one or more of the claims 1 to 10, wherein said control means (74, 92) controls a process parameter of said first means (10).
Claim 13
Independent Claim
31 words
A device as set forth in one or more of the claims 1 to 11, wherein the metal workpiece (12) is a wire and the other workpiece (14) is a pad.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.