Patent US5354422A successfully refreshed from Google Patents.
US5354422A
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US
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Process for producing leadframe material for semiconductor
Assignee: Dai Nippon Printing Co Ltd
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Filing: 1992-03-11
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Granted: 1994-10-11
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Expires: 2012-03-11
Abstract
Abstract A process for producing a leadframe for a semiconductor including (i) providing nickel or nickel-base alloy plating layers on both sides of a base material including an iron-base material or a copper-base material by electroplating or chemical plating so as to have a single layer thickness in the range of from 3 to 20 microns, (ii) applying a photoresist on both sides of the leadframe material produced in step (i) and forming a leadframe pattern by a patterning process and (iii) subjecting the leadframe material patterned in step (ii) to etching.
Inventors
- 👤 Kazunori Kato
- 👤 Hideo Hotta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:36
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/01; H10W70/04; H10W70/042; C; C23; C23F; C23F1/00; C23F1/02
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
96 words
A process for producing a leadframe for a semiconductor, comprising the steps of: (i) providing nickel or nickel-base alloy plating layers on both sides of a base material comprising an iron-base material or a copper-base material by electroplating or chemical plating so as to have a single layer thickness in the range of from 3 to 20 μm; (ii) applying a photoresist on both sides of the leadframe material produced in the step (i) and forming a leadframe pattern by a patterning process; and (iii) subjecting the leadframe material patterned in said step (ii) to etching.
Claim 2
Dependent Claim
96 words
A process for producing a leadframe for a semiconductor, comprising the steps of: (i) providing nickel or nickel-base alloy plating layers on both sides of a base material comprising an iron-base material or a copper-base material by electroplating or chemical plating so as to have a single layer thickness in the range of from 3 to 20 μm; (ii) applying a photoresist on both sides of the leadframe material produced in the step (i) and forming a leadframe pattern by a patterning process; and (iii) subjecting the leadframe material patterned in said step (ii) to etching.
Claim 3
Dependent Claim
21 words
The process of claim 1 wherein the patterning process comprises exposing and developing and the etching comprises etching with ferric chloride.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-10-10 | 1998-04-11 | 1998-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-10-10 | 2002-04-11 | 2002-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-10-10 | 2006-04-11 | 2006-10-11 | $7700.00 | Window Closed / Lapsed |