US3718969A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plastic encapsulated semiconductor assemblies
Assignee: Motorola Solutions Inc
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Filing: 1970-09-21
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Granted: 1973-03-06
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Expires: 1990-09-21
Abstract
Abstract A plastic encapsulated, high-frequency power transistor assembly having a metallized ceramic base and a metallic heat sink is fabricated by a method which includes the use of a thin, substantially flat lead frame member having at least four inwardly projecting, substantially coplanar electroconductive leads and a bridging portion integral therewith connecting the ends of two of said leads. The lead ends are bonded to corresponding metallized areas of the ceramic base, one of said metallized areas having a centrally extended configuration adapted for die bonding of the semiconductor unit. The assembly is then completed by the attachment of a metallic stud to the opposite side of the ceramic base, wire bonding of the emitter region to the bridging portion of the lead frame, wire bonding of the base region to the remaining lead, and a final step of plastic encapsulation.
Inventors
- 👤 E Segerson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:13
CPC Classifications
H; H10; H10W; H10W74/00; H10W74/10; H10W74/111; H10W74/114; H10W70/00; H10W70/40; H10W70/481; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49121
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
232 words
A method for the assembly of a semicon-ductor device comprising the steps of: providing a thin, substantially flat one-piece lead frame having a central area and at least four lead portions extending from said central area outwardly in said frame, with at least two of said lead portions extending in opposite directions from one another, and having a bridging portion integral at each end thereof with said two lead portions, said bridging portion extending between said two lead portions and shaped so as to lie in a different plane for substantially all of the area thereof than the plane in which the two connected lead portions lie, providing a portion of insulating material having metallized areas on one face thereof, connecting each lead portion at the inner end thereof to a metallized area, providing a semiconductor unit having electrodes thereon and bonding said unit to a metallized area, with said semiconductor unit in a plane below the bridging portion which extends for an area thereof in a plane above the plane of the semiconductor unit, connecting at least one electrode of the semiconductor unit to said bridging portion, connecting other electrodes of said unit to corresponding lead portions, encapsulating said semiconductor unit, said metallized areas, and the inner end of each lead portion to provide a housing therefor, and severing excess portions of the lead frame to complete a packaged semiconductor device.
Claim 2
Independent Claim
232 words
A method for the assembly of a semicon-ductor device comprising the steps of: providing a thin, substantially flat one-piece lead frame having a central area and at least four lead portions extending from said central area outwardly in said frame, with at least two of said lead portions extending in opposite directions from one another, and having a bridging portion integral at each end thereof with said two lead portions, said bridging portion extending between said two lead portions and shaped so as to lie in a different plane for substantially all of the area thereof than the plane in which the two connected lead portions lie, providing a portion of insulating material having metallized areas on one face thereof, connecting each lead portion at the inner end thereof to a metallized area, providing a semiconductor unit having electrodes thereon and bonding said unit to a metallized area, with said semiconductor unit in a plane below the bridging portion which extends for an area thereof in a plane above the plane of the semiconductor unit, connecting at least one electrode of the semiconductor unit to said bridging portion, connecting other electrodes of said unit to corresponding lead portions, encapsulating said semiconductor unit, said metallized areas, and the inner end of each lead portion to provide a housing therefor, and severing excess portions of the lead frame to complete a packaged semiconductor device.
Claim 3
Dependent Claim
51 words
A method as defined in claim 1 wherein at least one of said lead portions has an aperture therein adjacent the inner end thereof, and including the step of forcing plastic through said aperture during the encapsulation step to increase the mechanical strength of the ultimate package for the semiconductor device.
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) | 1976-03-05 | 1976-09-04 | 1977-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-05 | 1980-09-04 | 1981-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-05 | 1984-09-04 | 1985-03-06 | $7700.00 | Window Closed / Lapsed |