Patent US5304841A successfully refreshed from Google Patents.
US5304841A
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Lead frame
Assignee: Rohm Co Ltd
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Filing: 1993-04-12
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Granted: 1994-04-19
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Expires: 2013-04-12
Abstract
Abstract A lead frame for a rectangular flat package has dumb bars connecting the lead terminals and dam bar coupling portions at the corners of the frame in which the coupling portions are notched to permit the adjacent dam bars to have the same length as the other dam bars, permitting them to be cut away by the same punch. This arrangement permits an increase in the length of the nicked part of the corner of the resin body of the flat package, at which a gate for injection-molding of a resin is located, thereby avoiding chipping of the resin body when excess resin from the injection is removed.
Inventors
- 👤 Atsuhito Negoro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:53
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/40; H10W70/421; H10W70/01; H10W70/04; H10W70/048
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
126 words
A lead frame for a rectangular flat package having lead terminals extending outwardly through the peripheral sides of a resin body comprising a lead frame having a rectangular array of lead terminals and a plurality of dam bars connecting adjacent lead terminals along each side of the lead frame, and dam bar coupling portions at the corners of the array connecting the dam bars at the ends of adjacent sides of the lead frame, at least one of the dam bar coupling portions being formed with notches at the locations where adjacent dam bars are connected to it so that the length of the dam bars connected by that coupling portions is equal to the length of each of the dam bars connecting adjacent lead terminals.
Claim 2
Dependent Claim
126 words
A lead frame for a rectangular flat package having lead terminals extending outwardly through the peripheral sides of a resin body comprising a lead frame having a rectangular array of lead terminals and a plurality of dam bars connecting adjacent lead terminals along each side of the lead frame, and dam bar coupling portions at the corners of the array connecting the dam bars at the ends of adjacent sides of the lead frame, at least one of the dam bar coupling portions being formed with notches at the locations where adjacent dam bars are connected to it so that the length of the dam bars connected by that coupling portions is equal to the length of each of the dam bars connecting adjacent lead terminals.
Claim 3
Dependent Claim
20 words
A lead frame for a rectangular flat package according to claim 1, wherein said notches are formed into a U-shape.
References Cited (Backward Citations)
US4301464A
Cited
JPH03188655A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-04-18 | 1997-10-18 | 1998-04-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-04-18 | 2001-10-18 | 2002-04-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-04-18 | 2005-10-18 | 2006-04-19 | $7700.00 | Window Closed / Lapsed |