US5070039A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making an integrated circuit using a pre-served dam bar to reduce mold flash and to facilitate flash removal
Assignee: Texas Instruments Inc
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Filing: 1989-04-13
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Granted: 1991-12-03
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Expires: 2009-04-13
Abstract
Abstract A lead from 10 carries an integrated circuit on a die support pad 14. The lead frame has a dam bar including a transverse portion that extends between adjacent leads (20) for limiting mold flash. The dam bar transverse portion 26 is entirely severed from the adjacent leads for final removal by a metal punch 33 along with the supporting web 16.
Inventors
- 👤 Richard E. Johnson
- 👤 Dennis D. Davis
- 👤 David R. Kee
- 👤 John W. Orcutt
- 👤 Angus W. Hightower
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:09
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/40; H10W70/421; H10W70/01; H10W70/04; H10W70/048; H10W72/00; H10W72/50; H10W72/541; H10W72/5449; H10W74/00; H10W90/00; H10W90/701; H10W90/751; H10W90/756; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49121
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
120 words
A process for assembling an integrated circuit comprising the steps of: providing a lead frame with at least one pair of adjoining leads and a dam bar having a transverse portion extending between said leads and having a lateral portion, narrower than said transverse portion and extending from the transverse portion to a supporting web; entirely severing the transverse portion of said dam bar from the leads; joining an integrated circuit to the leads; subsequently encapsulating the integrated circuit in an insulating, molding compound; defining the outer molded edge of the molding compound between the leads with the entirely severed transverse portion of said dam bar; and finally severing the lateral portion of the dam bar from the supporting web.
Claim 2
Dependent Claim
120 words
A process for assembling an integrated circuit comprising the steps of: providing a lead frame with at least one pair of adjoining leads and a dam bar having a transverse portion extending between said leads and having a lateral portion, narrower than said transverse portion and extending from the transverse portion to a supporting web; entirely severing the transverse portion of said dam bar from the leads; joining an integrated circuit to the leads; subsequently encapsulating the integrated circuit in an insulating, molding compound; defining the outer molded edge of the molding compound between the leads with the entirely severed transverse portion of said dam bar; and finally severing the lateral portion of the dam bar from the supporting web.
Claim 3
Dependent Claim
33 words
The process of claim 1 wherein before the step of encapsulating the integrated circuit, the entirely severed transverse portion of said dam bar is repositioned between the leads to dam said molding compound.
Claim 4
Dependent Claim
38 words
The process of claim 1 wherein before the step of encapsulating the integrated circuit, the entirely severed transverse portion of said dam bar is press fitted into its original position between the leads to dam said molding compound.
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) | 1994-12-02 | 1995-06-03 | 1995-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-02 | 1999-06-03 | 1999-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-02 | 2003-06-03 | 2003-12-03 | $7700.00 | Window Closed / Lapsed |