Patent US5750423A successfully refreshed from Google Patents.
US5750423A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for encapsulation of semiconductor devices with resin and leadframe therefor
Assignee: I Pex Inc
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Filing: 1995-08-25
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Granted: 1998-05-12
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Expires: 2015-08-25
Abstract
Abstract A leadframes is provided with at least one supporting portion extending from an island thereof in the direction opposite to a surface on which a semiconductor chip is mounted, so that the supporting portion comes into contact with a bottom surface of a cavity of a mold for encapsulation of semiconductor chips with a resin when said mold is closed.
Inventors
- 👤 Masaaki Ishii
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:12
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/40; H10W70/411; H10W74/00; H10W74/01; H10W74/016; H10W90/00; H10W90/701; H10W90/751; H10W90/756
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
165 words
A method for encapsulating semiconductor chips with a resin, comprising the steps of loading leadframes with semiconductor chips into a mold so as to place semiconductor chips in cavities of the mold, said semiconductor chips being mounted on islands of said leadframes and wire-bonded to leads of said leadframes, and encapsulating said semiconductor chips on rhe leadframe with a molten resin, characterized in that each of said leadframes is provided with at least one supporting portion extending from the island thereof in the direction opposite to a chip-mounted surface so that said at least one supporting portion comes into contact with a bottom surface of the cavity of said mold when said mold is closed, said at least one supporting portion being formed, by bending a part of said island, into a configuration such tht it comes into point-contact with the bottom surface of the mold when the mold is closed to minimize a surface area of the leadframe exposed out of the molded resin.
Claim 2
Independent Claim
165 words
A method for encapsulating semiconductor chips with a resin, comprising the steps of loading leadframes with semiconductor chips into a mold so as to place semiconductor chips in cavities of the mold, said semiconductor chips being mounted on islands of said leadframes and wire-bonded to leads of said leadframes, and encapsulating said semiconductor chips on rhe leadframe with a molten resin, characterized in that each of said leadframes is provided with at least one supporting portion extending from the island thereof in the direction opposite to a chip-mounted surface so that said at least one supporting portion comes into contact with a bottom surface of the cavity of said mold when said mold is closed, said at least one supporting portion being formed, by bending a part of said island, into a configuration such tht it comes into point-contact with the bottom surface of the mold when the mold is closed to minimize a surface area of the leadframe exposed out of the molded resin.
Claim 3
Dependent Claim
39 words
The method for encapsulation of semiconductor chips with a resin according to claim 1, wherein said at least one supporting portion has a configuration selected from the group consisting of a triangular shape, a polygon, semi-circle or a semi-oval.
Claim 4
Dependent Claim
63 words
The method for encapsulation of semiconductor chips with a resin according to claim 1, wherein said leadframe is provided with rectangular islands, and wherein said at least one supporting portion is formed by bending at least one comer of each of said rectangular islands in the direction opposite to a surface of the island on which said semiconductor chip is to be mounted.
References Cited (Backward Citations)
US4633583A
Cited
US4612564A
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US5053855A
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JPH0419641A
Cited
US5367766A
Cited
US5147821A
Cited
US5512781A
Cited
US5302849A
Cited
US5527743A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-05-11 | 2001-11-10 | 2002-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-05-11 | 2005-11-10 | 2006-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-05-11 | 2009-11-10 | 2010-05-12 | $7700.00 | Window Closed / Lapsed |