US5083186A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor device lead frame with rounded edges
Assignee: Mitsubishi Electric Corp
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Filing: 1990-06-08
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Granted: 1992-01-21
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Expires: 2010-06-08
Abstract
Abstract A leadframe including a die pad and inner leads the die pad having a substantially rounded edge configuration with no sharp edge, and the inner leads each having a trapezoidal cross-sectional configuration. In this construction, stresses are not concentrated in the end portion of the die pad due to temperature stresses and therefore, no cracks are formed in the resin encapsulating ICs. Accordingly, highly reliable ICS can be provided.
Inventors
- 👤 Kazuhisa Okada
- 👤 Akihiro Okamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 03:30
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/40; H10W70/421; H10W70/424; H10W70/01; H10W70/04; H10W70/042; H10W70/411; H10W90/00; H10W90/811; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49121
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
91 words
A leadframe for a semiconductor device comprising: a die pad having opposed first and second faces on which a semiconductor device may be mounted and side surfaces extending between said first and second faces wherein said side surfaces have a substantially rounded configuration in a cross-section taken substantially perpendicular to the first face; a plurality of inner leads, each inner lead having an end disposed adjacent said die pad; and a plurality of outer leads, each outer lead being connected to a corresponding inner lead and having a trapezoidal cross-sectional configuration.
Claim 2
Dependent Claim
91 words
A leadframe for a semiconductor device comprising: a die pad having opposed first and second faces on which a semiconductor device may be mounted and side surfaces extending between said first and second faces wherein said side surfaces have a substantially rounded configuration in a cross-section taken substantially perpendicular to the first face; a plurality of inner leads, each inner lead having an end disposed adjacent said die pad; and a plurality of outer leads, each outer lead being connected to a corresponding inner lead and having a trapezoidal cross-sectional configuration.
Claim 3
Dependent Claim
26 words
A leadframe according to claim 1 wherein the end of each of said inner leads has a substantially rounded cross-sectional edge configuration with no sharp edge.
References Cited (Backward Citations)
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US4707418A
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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) | 1995-01-20 | 1995-07-22 | 1996-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-01-20 | 1999-07-22 | 2000-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-01-20 | 2003-07-22 | 2004-01-21 | $7700.00 | Window Closed / Lapsed |