US5420752A
Expired / Lapsed
US
⏱️ 0.0 years remaining
GPT system for encapsulating an integrated circuit package
Assignee: LSI Corp
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Filing: 1993-08-18
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Granted: 1995-05-30
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Expires: 2013-08-18
Abstract
Abstract The present invention provides a method for fabricating an integrated circuit package, as well the resulting integrated circuit package, which retains a heatsink in close communication with a mold cavity. This precludes any encapsulant from flowing between the heatsink and the inner surface of a mold cavity. As a consequence, the bottom of the heatsink is not encapsulated and is thus exposed. This is accomplished by including posts, attached to the leadframe assembly, which have the function of exerting a downward force on a leadframe assembly and, in turn, on the heatsink. Tie bars, which are nonfunctional parts of a leadframe assembly, can be utilized as posts by bending the posts into an upright position.
Inventors
- 👤 Patrick Variot
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 03:55
CPC Classifications
H; H10; H10W; H10W74/00; H10W74/01; H10W74/016; H10W40/00; H10W40/70; H10W40/77; H10W40/778; H10W90/00; H10W90/701; H10W90/751; H10W90/756; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49121; Y10T29/49124; Y10T29/4913; Y10T29/49146; Y10T29/49169; Y10T29/49171
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
131 words
An integrated circuit package, comprising: (a) a heatsink having a first and second surface; (b) a semiconductor die in thermal communication with a portion of the first surface of said heatsink; (c) a leadframe assembly disposed over and substantially parallel to the first surface of said heatsink and around said semiconductor die, said leadframe assembly electrically connected to said semiconductor die, said leadframe assembly including a plurality of leadframe fingers extending into a plurality of lead tips that are adapted for connection to external circuits, said leadframe assembly further including a plurality of posts extending substantially perpendicular to and away from said first heatsink surface; and (d) an encapsulant enclosing said semiconductor die, said heatsink except the second surface thereof, and said leadframe assembly except for the plurality of lead tips.
Claim 2
Dependent Claim
131 words
An integrated circuit package, comprising: (a) a heatsink having a first and second surface; (b) a semiconductor die in thermal communication with a portion of the first surface of said heatsink; (c) a leadframe assembly disposed over and substantially parallel to the first surface of said heatsink and around said semiconductor die, said leadframe assembly electrically connected to said semiconductor die, said leadframe assembly including a plurality of leadframe fingers extending into a plurality of lead tips that are adapted for connection to external circuits, said leadframe assembly further including a plurality of posts extending substantially perpendicular to and away from said first heatsink surface; and (d) an encapsulant enclosing said semiconductor die, said heatsink except the second surface thereof, and said leadframe assembly except for the plurality of lead tips.
Claim 3
Independent Claim
187 words
A system for fabricating an integrated circuit package, comprising: (a) a mold in a closed position, said closed mold having an inside surface; (b) a heatsink having a first and second surface; (c) a semiconductor die in thermal communication with a portion of the first surface of said heatsink; (d) a leadframe assembly disposed over the first surface of said heatsink and around said semiconductor die, said leadframe assembly electrically connected to said semiconductor die, said leadframe assembly including a plurality of leadframe fingers extending into a plurality of lead tips that are adapted for connection to external circuits, said leadframe assembly further including a plurality of posts extending substantially perpendicular to and away from said heatsink, the plurality of posts engaging the inside surface of said closed mold; (e) said semiconductor die, said heatsink and said leadframe assembly, including the plurality of posts but not said plurality of lead tips, being located within said closed mold; and (f) a means for injecting encapsulant into said closed mold, whereby said encapsulant is substantially precluded from flowing between the inside surface of said closed mold and said heatsink.
Claim 4
Independent Claim
187 words
A system for fabricating an integrated circuit package, comprising: (a) a mold in a closed position, said closed mold having an inside surface; (b) a heatsink having a first and second surface; (c) a semiconductor die in thermal communication with a portion of the first surface of said heatsink; (d) a leadframe assembly disposed over the first surface of said heatsink and around said semiconductor die, said leadframe assembly electrically connected to said semiconductor die, said leadframe assembly including a plurality of leadframe fingers extending into a plurality of lead tips that are adapted for connection to external circuits, said leadframe assembly further including a plurality of posts extending substantially perpendicular to and away from said heatsink, the plurality of posts engaging the inside surface of said closed mold; (e) said semiconductor die, said heatsink and said leadframe assembly, including the plurality of posts but not said plurality of lead tips, being located within said closed mold; and (f) a means for injecting encapsulant into said closed mold, whereby said encapsulant is substantially precluded from flowing between the inside surface of said closed mold and said heatsink.
Claim 5
Dependent Claim
16 words
The apparatus as recited in claim 2, wherein the leadframe assembly includes at least four posts.
Claim 6
Dependent Claim
25 words
The apparatus as recited in claim 2, wherein the leadframe assembly includes a plurality of tie bars from which the plurality of posts are formed.
Claim 7
Dependent Claim
34 words
The apparatus as recited in claim 2, wherein the plurality of posts extend beyond the inside surface of the mold so that the plurality of posts are springingly compressed when the mold is closed.
References Cited (Backward Citations)
US3622419A
Cited
US3706840A
Cited
US3930114A
Cited
US4701999A
Cited
US4902606A
Cited
US5091341A
Cited
US5252783A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-05-29 | 1998-11-28 | 1999-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-05-29 | 2002-11-28 | 2003-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-05-29 | 2006-11-28 | 2007-05-30 | $7700.00 | Window Closed / Lapsed |