US4523218A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lead frame for integrated circuits and method of fabricating the same
Assignee: Sumitomo Metal Mining Co Ltd
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Filing: 1982-09-27
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Granted: 1985-06-11
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Expires: 2002-09-27
Abstract
Abstract A lead frame for integrated circuits has a central opening in which there is fitted a metal piece having alternate recesses and projections, the recesses fitting over inner ends of leads of the lead frame and the projections fitting in gaps between the inner lead ends. The metal piece includes slots and cut-outs to allow its comb-shaped members to bend independently of each other. After the lead frame had been fused to a ceramic substrate, the metal piece can be moved by being pulled upwardly with a relatively small force applied. The metal piece has a pair of pull tabs. For fabricating such a lead frame, the metal piece is stamped out of an integral metal plate structure having the leads and support frame integral with the leads. Then, the stamped metal piece is pushed back so as to fit with the leads of the lead frame.
Inventors
- 👤 Yoshihisa Kato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:34
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/40; H10W70/411; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49121
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
133 words
A lead frame for use in an integrated circuits package, comprising: a multiplicity of spaced leads extending outwardly from a central opening and having inner and outer ends; a support frame integrally supporting said outer ends of said leads; and a metal piece disposed in said central opening and having in peripheral edges thereof alternate recesses and projections, said recesses fitting over and receiving said inner ends and said projections fitting in gaps between said inner ends, said metal piece also having slots spaced inwardly from said recesses and projections and cut-outs defined between said slots, said slots and said cut-outs jointly dividing said metal piece into a plurality of comb-shaped members interconnected by a plurality of bendable portions defined therebetween by said slots and said cut-outs, said comb-shaped members being independently bendable.
Claim 2
Dependent Claim
133 words
A lead frame for use in an integrated circuits package, comprising: a multiplicity of spaced leads extending outwardly from a central opening and having inner and outer ends; a support frame integrally supporting said outer ends of said leads; and a metal piece disposed in said central opening and having in peripheral edges thereof alternate recesses and projections, said recesses fitting over and receiving said inner ends and said projections fitting in gaps between said inner ends, said metal piece also having slots spaced inwardly from said recesses and projections and cut-outs defined between said slots, said slots and said cut-outs jointly dividing said metal piece into a plurality of comb-shaped members interconnected by a plurality of bendable portions defined therebetween by said slots and said cut-outs, said comb-shaped members being independently bendable.
Claim 3
Dependent Claim
28 words
A lead frame according to claim 1, wherein said recesses have a depth which is 0.1 to 4 times the width of the inner ends of said leads.
Claim 4
Dependent Claim
28 words
The lead frame according to claim 2, wherein said recesses have a depth which is 0.5 to 1 times the width of the inner ends of said leads.
Claim 5
Dependent Claim
30 words
A lead frame according to claim 1, wherein said slots are spaced from said recesses by a distance which is at least two times the thickness of said metal piece.
Claim 6
Dependent Claim
28 words
A lead frame according to claim 1, wherein said slots and said cut-outs have a width which is 0.5 to 1.5 times the thickness of the metal piece.
Claim 7
Dependent Claim
33 words
A lead frame according to claim 1, wherein said slots are spaced from adjacent ones across said bendable portions by a distance which is substantially equal to the thickness of said metal piece.
Claim 8
Dependent Claim
26 words
A lead frame according to claim 1, wherein said cut-outs are defined respectively in corners of said metal piece and extend substantially in diagonal directions thereof.
Claim 9
Dependent Claim
26 words
A lead frame according to claim 1, wherein said metal piece has at least one bent pull tab for removing the metal piece from said leads.
Claim 10
Dependent Claim
15 words
A lead frame according to claim 8, wherein said bent pull tab has an opening.
Claim 11
Dependent Claim
31 words
A lead frame according to claim 1, wherein said metal piece has a pair of opposite bent pull tabs disposed symmetrically with respect to a central axis of said metal piece.
Claim 12
Dependent Claim
18 words
A lead frame according to claim 10, wherein said pull tabs have a pair of aligned openings, respectively.
References Cited (Backward Citations)
US4137546A
Cited
US4415917A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-06-10 | 1988-12-10 | 1989-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-10 | 1992-12-10 | 1993-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-10 | 1996-12-10 | 1997-06-11 | $7700.00 | Window Closed / Lapsed |