US3729573A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plastic encapsulation of semiconductor devices
Assignee: Motorola Solutions Inc
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Filing: 1971-01-25
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Granted: 1973-04-24
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Expires: 1991-01-25
Abstract
Abstract A first plastic encapsulated subassembly has a cup-shaped recess with the sides of the cup having a taper of about 30* and a heat sink opposite the cup. The assembly is placed in a cavity of a mold with a second heat sink in contact with the subassembly heat sink and resting on one face of the mold cavity. A mold pin is inserted into the cup-shaped recess, forcing the subassembly, using a precalculated and controlled deformation of the cup, heat sink and the one mold face together such that the later injected plastic encapsulating material does not flow therebetween to provide a good thermal path from the subassembly heat sink to an outer face of the completed plastic encapsulated assembly.
Inventors
- 👤 T Dunn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:35
CPC Classifications
H; H10; H10W; H10W74/00; H10W74/01; H10W74/016; H10W40/00; H10W40/70; H10W40/77; H10W40/778
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
169 words
A plastic encapsulated electrical unit, including the combination, a first heat sink disposed along one surface with no plastic encapsulating material thereover, a second metal heat sink member disposed on the first-mentioned heat sink member with no plastic encapsulating material therebetween, a first body of plastic encapsulating material securely holding said second-mentioned heat sink and having a conductor means encapsulated therein and extending outwardly to make electrical circuit connections outside of said first body of plastic encapsulated material, a second body of plastic encapsulating material covering said first body and said conductor means except for portions of said conductor means extending outwardly of said second body and for said one face of said first heat sink, an aperture in said second body of plastic encapsulating material extending to said first body of plastic encapsulating material opposite said heat sinks, and a cup-shaped recess on said first body of plastic encapsulating material facing said aperture with the walls of the recess being tapered toward an apex remote from said aperture.
Claim 2
Dependent Claim
169 words
A plastic encapsulated electrical unit, including the combination, a first heat sink disposed along one surface with no plastic encapsulating material thereover, a second metal heat sink member disposed on the first-mentioned heat sink member with no plastic encapsulating material therebetween, a first body of plastic encapsulating material securely holding said second-mentioned heat sink and having a conductor means encapsulated therein and extending outwardly to make electrical circuit connections outside of said first body of plastic encapsulated material, a second body of plastic encapsulating material covering said first body and said conductor means except for portions of said conductor means extending outwardly of said second body and for said one face of said first heat sink, an aperture in said second body of plastic encapsulating material extending to said first body of plastic encapsulating material opposite said heat sinks, and a cup-shaped recess on said first body of plastic encapsulating material facing said aperture with the walls of the recess being tapered toward an apex remote from said aperture.
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) | 1976-04-23 | 1976-10-23 | 1977-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-23 | 1980-10-23 | 1981-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-23 | 1984-10-23 | 1985-04-24 | $7700.00 | Window Closed / Lapsed |