US4246697A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing RF power semiconductor package
Assignee: Motorola Solutions Inc
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Filing: 1978-04-06
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Granted: 1981-01-27
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Expires: 1998-04-06
Abstract
Abstract High frequency power transistor carriers are made by bonding a metalized ceramic base to a lead frame strip, subsequently gold plating the resultant structure and then cutting the lead frame strip to isolate the base and collector leads while still maintaining the transistor carriers in strip form. Transistor dice are then attached to each ceramic carrier, and each transistor carrier in the strip is then electrically tested. The individual carriers are then separated from the lead frame strip. The individual carrier has wide base and collector leads extending outward from the ceramic base for a substantial distance and then the base and collector leads are narrowed down. When the individual transistor carrier is used in combination with a hybrid assembly, a reduction in lead inductance and total hybrid package size is obtained while exact carrier placement relative to the hybrid assembly is not required.
Inventors
- 👤 John M. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:03
CPC Classifications
H; H10; H10W; H10W44/00; H10W44/20; H10W70/00; H10W70/40; H10W70/453; H10W70/481; H10W70/60; H10W70/62; H10W70/65; H10W70/658; H10W76/00; H10W76/10; H10W76/12; H10W76/15; H10W76/157; H10W44/226; H10W72/00; H10W72/071; H10W72/075; H10W72/07551; H10W72/50; H10W72/541; H10W72/5445; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49121; Y10T29/49124; Y10T29/4913
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
193 words
A method for manufacturing semiconductor device packages comprising the steps of: metalizing with substantially gold free metalizations the bottom surface and a plurality of isolated top surface areas on a plurality of ceramic carriers; bonding a number of finger projections of a substantially gold free metal lead frame strip to a number of said top metalized areas on each of said plurality of ceramic carriers to form an assembly electrically and mechanically connected by said lead frame strip; then electroplating with gold, simultaneously, said lead frame strip and said number of bonded top metalized areas on said plurality of ceramic carriers while said number of top metalized areas of said plurality of carriers are still mechanically and electrically bonded to said lead frame strip; the method including prior to the step of bonding said gold free lead frame strip to said number of gold free metalizations, the steps of: cladding said substantially gold free metal lead frame strip with an exterior silver cladding, providing a nickel exterior overcoat to said top surface gold free metalizations, and wherein said bonding step further comprises bonding said silver cladding to said top metalization nickel exterior overcoat.
Claim 2
Independent Claim
193 words
A method for manufacturing semiconductor device packages comprising the steps of: metalizing with substantially gold free metalizations the bottom surface and a plurality of isolated top surface areas on a plurality of ceramic carriers; bonding a number of finger projections of a substantially gold free metal lead frame strip to a number of said top metalized areas on each of said plurality of ceramic carriers to form an assembly electrically and mechanically connected by said lead frame strip; then electroplating with gold, simultaneously, said lead frame strip and said number of bonded top metalized areas on said plurality of ceramic carriers while said number of top metalized areas of said plurality of carriers are still mechanically and electrically bonded to said lead frame strip; the method including prior to the step of bonding said gold free lead frame strip to said number of gold free metalizations, the steps of: cladding said substantially gold free metal lead frame strip with an exterior silver cladding, providing a nickel exterior overcoat to said top surface gold free metalizations, and wherein said bonding step further comprises bonding said silver cladding to said top metalization nickel exterior overcoat.
Claim 3
Dependent Claim
33 words
The method according to claim 1 which includes the additional steps of mechanically coupling a semiconductor device to one of said top metalized areas on each of said plurality of said ceramic carriers.
Claim 4
Dependent Claim
38 words
The method according to claim 2 wherein said semiconductor chip device is a transistor and which includes the additional step of coupling electrically the electrical terminals of said semiconductor device to a number of said top metalized areas.
Claim 5
Dependent Claim
69 words
The method according to claim 3 which includes the additional steps of; isolating electrically from said lead frame strip, by cutting said strip, an input and an output top metalized area on each of said ceramic carriers while keeping at least one connection from each of said carriers to said lead frame strip intact, and testing electrically the semiconductor chip device on each of said plurality of ceramic carriers.
Claim 6
Dependent Claim
33 words
The method according to claim 1, wherein the step of cladding is further defined as applying said silver cladding to one side of a substantially nickel base which form said lead frame strip.
Claim 7
Dependent Claim
39 words
The method according to claim 5 which, after the cladding step, includes the step of punching out the silver clad nickel base to form said number of finger projections to be bonded to said gold free top metalized areas.
References Cited (Backward Citations)
US3544857A
Cited
US3520054A
Cited
GB1191093A
Cited
US3549782A
Cited
US3729820A
Cited
US3864727A
Cited
US3698074A
Cited
US3691289A
Cited
US3902148A
Cited
US3713066A
Cited
US3872583A
Cited
JPS4948266A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-27 | 1984-07-28 | 1985-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-27 | 1988-07-28 | 1989-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-27 | 1992-07-28 | 1993-01-27 | $7700.00 | Window Closed / Lapsed |