Patent US5343073A successfully refreshed from Google Patents.
US5343073A
Expired / Lapsed
US
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Lead frames having a chromium and zinc alloy coating
Assignee: GBC Metals LLC
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Filing: 1993-01-06
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Granted: 1994-08-30
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Expires: 2013-01-06
Abstract
Abstract There is provided a lead frame with enhanced adhesion to a polymer resin. The lead frame is coated with a thin layer of containing a mixture of chromium and zinc. A mixture of chromium and zinc with the zinc-to-chromium ratio in excess of about 4:1 is most preferred. The coated lead frames exhibit improved adhesion to a polymeric resin.
Inventors
- 👤 Arvind Parthasarathi
- 👤 Deepak Mahulikar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:23
CPC Classifications
H; H10; H10W; H10W76/00; H10W76/60; H10W72/00; H10W70/00; H10W70/40; H10W70/456; H10W70/457; H10W74/00; H10W74/10; H10W74/111; H10W72/071; H10W72/075; H10W72/07531; H10W72/07532; H10W72/07537; H10W72/30; H10W72/381; H10W72/50; H10W72/551; H10W72/552; H10W72/5522; H10W72/59; H10W72/851; H10W72/874; H10W72/884; H10W72/90; H10W72/951; H10W72/952; H10W90/00; H10W90/701; H10W90/731; H10W90/736; H10W90/751; H10W90/756
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
40 words
A leadframe comprising: an electrically conductive metal substrate being a copper base alloy and formed into a plurality of leads, said substrate coated with at least one metallic layer, the outer most layer containing a mixture of chromium and zinc.
Claim 2
Dependent Claim
40 words
A leadframe comprising: an electrically conductive metal substrate being a copper base alloy and formed into a plurality of leads, said substrate coated with at least one metallic layer, the outer most layer containing a mixture of chromium and zinc.
Claim 3
Dependent Claim
26 words
The lead frame of claim 1 wherein said electrically conductive metal substrate is a copper base alloy containing 0.05%-0.15% by weight zirconium and the balance copper.
Claim 4
Dependent Claim
30 words
The lead frame of claim 1 wherein said electrically conductive metal substrate is a copper base alloy containing 2.1%-2.6% by weight iron, 0.015%-0.15% phosphorous, 0.05%-0.20% zinc and the balance copper.
Claim 5
Dependent Claim
32 words
The lead frame of claim 1 wherein said electrically conductive metal substrate is a copper base alloy containing 1.0%-2.0% by weight iron, 0.01%-0.35% phosphorous, 0.30%-1.3% cobalt, 0.10%-1.0% tin and the balance copper.
Claim 6
Dependent Claim
30 words
The lead frame of claim 1 wherein said electrically conductive metal substrate is a copper base alloy containing 0.30%-1.2% by weight iron, 0.10%-0.40% phosphorous, 0.01%-0.20% magnesium and the balance copper.
Claim 7
Dependent Claim
32 words
The lead frame of claim 1 wherein said electrically conductive metal substrate is a copper base alloy containing 1.7%-2.3% by weight tin, 0.1%-0.4% nickel, up to 0.15% phosphorous and the balance copper.
Claim 8
Dependent Claim
28 words
The lead frame of claim 1 wherein said electrically conductive metal substrate is a copper base alloy containing 0.05%-0.15% by weight iron, 0.025%-0.040% phosphorous and the balance copper.
Claim 9
Dependent Claim
30 words
The lead frame of claim 1 wherein said electrically conductive metal substrate is a copper base alloy containing 0.5%-1.5% by weight iron, 0.5%-1.5% tin, 0.01%-0.35% phosphorous and the balance copper.
Claim 10
Dependent Claim
30 words
The lead frame of claim 1 wherein said electrically conductive metal substrate is a copper base alloy containing 0.15%-0.40% by weight chromium, 0.01%-0.40% titanium, 0.02%-0.07% silicon and the balance copper.
Claim 11
Dependent Claim
30 words
The lead frame of claim 1 wherein said electrically conductive metal substrate is a copper base alloy containing 0.8%-1.8% by weight nickel, 0.15%-0.35% silicon, 0.01%-0.05% phosphorous and the balance copper.
Claim 12
Dependent Claim
30 words
The lead frame of claim 1 wherein said electrically conductive metal substrate is a copper base alloy containing 2%-4.8% by weight nickel, 0.2%-1.4% silicon, 0.05%-0.45% magnesium and the balance copper.
Claim 13
Dependent Claim
30 words
The lead frame of claim 1 wherein said electrically conductive metal substrate is a copper base alloy containing 0.30%-0.40% by weight chromium, 0.20%-0.30% tin, 0.15%-0.25% zinc and the balance copper.
Claim 14
Dependent Claim
30 words
The lead frame of claim 1 wherein said electrically conductive metal substrate is a copper base alloy containing 2.7%-3.7% by weight nickel, 0.2%-1.2% silicon, 0.1%-0.5% zinc and the balance copper.
Claim 15
Dependent Claim
30 words
The lead frame of claim 1 wherein said electrically conductive metal substrate is a copper base alloy containing 1.9%-2.9% by weight nickel, 0.20%-0.60% silicon, 0.10%-0.20% phosphorous and the balance copper.
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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) | 1997-08-29 | 1998-02-28 | 1998-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-08-29 | 2002-02-28 | 2002-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-08-29 | 2006-02-28 | 2006-08-30 | $7700.00 | Window Closed / Lapsed |