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Patent US3761783A successfully refreshed from Google Patents.
US3761783A
Expired / Lapsed
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Duel-mesa ring-shaped high frequency diode
Assignee: Unisys Corp
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Filing: 1972-02-02
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Granted: 1973-09-25
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Expires: 1992-02-02
Abstract
Abstract High frequency diodes are manufactured by methods in which extended dual means are formed upon semiconductor or other substrates, one mesa incorporating the active junction and another supporting the active mesa in reduced parasitic capacitive relation, with the substrate supporting the combination of mesas and with an efficient heat sink cooperating with the active mesa. Novel ring shaped diodes made according to the method feature a high degree of circular symmetry and therefore freedom from burn out, thermal compression bonding being used to perfect the bond between the active mesa and a diamond heat sink. Symmetry of the diode is assured by use of a photoresist mask generation technique employing a reduced rate of evaporation of the photoresist solvent.
Inventors
- 👤 H Kroger
- 👤 C Potter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 07:57
CPC Classifications
H; H10; H10W; H10W40/00; H10W40/10; H10D; H10D99/00; H10W99/00; Y; Y10; Y10S; Y10S438/00; Y10S438/942; Y10S438/948; Y10S438/95
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
80 words
A high frequency diode comprising: a substrate having at least one surface, a first annular semiconductor mesa projecting from said one surface, said first mesa having a first ring shaped surface substantially parallel to said one surface, a second annular semiconductor mesa smaller than said first mesa projecting from said first ring shaped surface, said second mesa having a second ring shaped surface substantially parallel to said one surface, and heat sink means bonded to said second ring shaped surface.
Claim 2
Dependent Claim
80 words
A high frequency diode comprising: a substrate having at least one surface, a first annular semiconductor mesa projecting from said one surface, said first mesa having a first ring shaped surface substantially parallel to said one surface, a second annular semiconductor mesa smaller than said first mesa projecting from said first ring shaped surface, said second mesa having a second ring shaped surface substantially parallel to said one surface, and heat sink means bonded to said second ring shaped surface.
Claim 3
Dependent Claim
58 words
Apparatus as described in claim 1 wherein said heat sink means comprises: diamond heat sink means having a surface, a metal layer of chromium plated on said diamond heat sink means surface, and a layer of high heat and high electrical conductivity metal plated on said chromium layer for thermal compression bonding to said second ring shaped surface.
Claim 4
Dependent Claim
17 words
Apparatus as described in claim 2 wherein said layer plated on said chromium layer consists of gold.
Claim 5
Dependent Claim
12 words
Apparatus as described in claim 1 wherein said substrate consists of gold.
Claim 6
Dependent Claim
14 words
Apparatus described in claim 1 wherein said substrate consists of type N+ semiconductor material.
Claim 7
Dependent Claim
16 words
Apparatus as described in claim 1 wherein said first mesa consists of type N+ semiconductor material.
Claim 8
Dependent Claim
83 words
Apparatus as described in claim 1 wherein said second mesa consists of: a type N+ semiconductor layer affixed to said first mesa first ring shaped surface, a type N semiconductor layer affixed to said type N+ layer, a type P semiconductor layer affixed to said type N layer, a metal chromium layer affixed to said type P layer, and a metal layer having high heat and electrical conduCtivity characteristics affixed to said chromium layer for thermal compression bonding to said heat sink means.
References Cited (Backward Citations)
US2973466A
Cited
US3201664A
Cited
US3283218A
Cited
US3457471A
Cited
US3487272A
Cited
US3516017A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-24 | 1977-03-26 | 1977-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-24 | 1981-03-26 | 1981-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-24 | 1985-03-26 | 1985-09-25 | $7700.00 | Window Closed / Lapsed |