Patent US5817544A successfully refreshed from Google Patents.
US5817544A
Expired / Lapsed
US
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Enhanced wire-bondable leadframe
Assignee: Olin Corp
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Filing: 1996-01-16
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Granted: 1998-10-06
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Expires: 2016-01-16
Abstract
Abstract A method for improving adhesion from a leadframe to a metallic wire is disclosed including using a laser beam to remove selected areas of an package adhesion enhancing layer to expose a layer on the leadframe which has a higher adhesion to metallic wires. The package adhesion enhancing layer is from the group consisting essentially of aluminum oxide, anti-tarnish finishes, and dielectrics. The exposed layer on the leadframe is selected from the group consisting essentially of silver, nickel, palladium.
Inventors
- 👤 Arvind Parthasarathi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:30
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/40; H10W70/456; H10W70/458; H10W74/00; H10W74/10; H10W74/111; H10W74/127; H10W76/00; H10W76/60; H10W72/00; H10W72/071; H10W72/075; H10W72/07531; H10W72/07532; H10W72/07533; H10W72/30; H10W72/381; H10W72/50; H10W72/531; H10W72/533; H10W72/534; H10W72/541; H10W72/5449; H10W72/551; H10W72/552; H10W72/5522; H10W72/5524; H10W72/5525; H10W72/851; H10W72/874; H10W72/884; H10W90/00; H10W90/701; H10W90/731; H10W90/736; H10W90/751; H10W90/756
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
67 words
A method for improving adhesion from a leadframe to a metallic wire comprising the steps of: (a) providing the leadframe substantially coated with a coating which has a lower adhesion to the metallic wire than the leadframe; (b) applying a laser beam to selected areas of the coating to remove the coating, whereby the temperature of said selected areas exceeds the reflow temperature of said selected areas.
Claim 2
Independent Claim
67 words
A method for improving adhesion from a leadframe to a metallic wire comprising the steps of: (a) providing the leadframe substantially coated with a coating which has a lower adhesion to the metallic wire than the leadframe; (b) applying a laser beam to selected areas of the coating to remove the coating, whereby the temperature of said selected areas exceeds the reflow temperature of said selected areas.
Claim 3
Dependent Claim
29 words
The method of claim 1, wherein the step of providing includes the substep of selecting the coating from the group consisting essentially of aluminum oxide, anti-tarnish finishes, and dielectrics.
Claim 4
Dependent Claim
26 words
The method of claim 1, wherein the step of providing includes the substep of providing a wire bond enhancing layer between the leadframe and the coating.
Claim 5
Dependent Claim
36 words
The method of claim 3, wherein the substep of providing a wire bond enhancing layer includes selecting the wire bond enhancing layer from the group consisting essentially of silver, nickel, palladium, gold, aluminum, and alloys thereof.
Claim 6
Dependent Claim
29 words
The method of claim 1, wherein the step of applying includes the substep of selecting the laser from the group consisting of CO 2 , excimer, and YAG lasers.
Claim 7
Dependent Claim
29 words
The method of claim 4, wherein the step of applying includes the substep of selecting the laser from the group consisting of CO 2 , excimer, and YAG lasers.
Claim 8
Independent Claim
55 words
A method of attaching a metallic wire to a leadframe comprising the steps of: (a) providing a leadframe; (b) applying a laser beam to a wire bonding site, whereby the temperature of said wire bonding site exceeds the reflow temperature of said wire bonding site; and (c) bonding the wire to the wire bonding site.
Claim 9
Independent Claim
55 words
A method of attaching a metallic wire to a leadframe comprising the steps of: (a) providing a leadframe; (b) applying a laser beam to a wire bonding site, whereby the temperature of said wire bonding site exceeds the reflow temperature of said wire bonding site; and (c) bonding the wire to the wire bonding site.
Claim 10
Dependent Claim
23 words
The method according of claim 7, wherein the step of bonding occurs while the leadframe is partially melted at the wire bonding site.
Claim 11
Dependent Claim
22 words
The method of claim 7, wherein the step of applying includes the step of providing the laser beam with an optical fiber.
Claim 12
Dependent Claim
26 words
The method of claim 7, wherein the step of applying includes the substep of exposing a leadframe surface by ablating any layers present on the leadframe.
Claim 13
Independent Claim
66 words
A method of attaching a metallic wire to a leadframe comprising the steps of: (a) providing a leadframe; (b) applying a laser beam to a wire bonding site, whereby the temperature of said wire bonding site exceeds the reflow temperature of said wire bonding site; and (c) bonding the wire to the wire bonding site, wherein said applying step and said bonding step occur nearly simultaneously.
Claim 14
Independent Claim
66 words
A method of attaching a metallic wire to a leadframe comprising the steps of: (a) providing a leadframe; (b) applying a laser beam to a wire bonding site, whereby the temperature of said wire bonding site exceeds the reflow temperature of said wire bonding site; and (c) bonding the wire to the wire bonding site, wherein said applying step and said bonding step occur nearly simultaneously.
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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) | 2001-10-05 | 2002-04-06 | 2002-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-10-05 | 2006-04-06 | 2006-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-10-05 | 2010-04-06 | 2010-10-06 | $7700.00 | Window Closed / Lapsed |