Patent US3689993A successfully refreshed from Google Patents.
US3689993A
Expired / Lapsed
US
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Fabrication of semiconductor devices having low thermal inpedance bonds to heat sinks
Assignee: Texas Instruments Inc
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Filing: 1971-07-26
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Granted: 1972-09-12
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Expires: 1991-07-26
Abstract
Abstract A layer of contact metallization is applied over the surface of a semiconductor slice having a P-N junction. A heat sink layer of high conductivity metal, such as copper, is applied over the contact metallization with a sufficient thickness to provide a predetermined heat dissipation for the P-N junction. A plurality of spaced apart discrete metal contacts are formed over the opposite surface of the semiconductor slice. Portions of the semiconductor slice are then removed between the metal contacts in order to form an array of discrete semiconductor devices, such as avalanche diodes, extending from the heat sink layer. The heat sink layer is then divided to provide a plurality of semiconductor devices attached to individual low thermal impedance heat sink members.
Inventors
- 👤 Neal Jay Tolar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:43
CPC Classifications
H; H10; H10N; H10N80/00; H10N80/10; H10N80/107; H10P; H10P54/00; H10W; H10W40/00; H10W40/10; H10W72/00; H10W72/30; H10W72/071; H10W72/073; H10W72/07331; H10W72/07336; H10W72/07337; H10W72/351; H10W72/353; H10W72/354; H10W72/50; H10W72/59
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
31 words
The method defined in claim 1 and further comprising: mounting said semiconductor substrate with an adhesive upon a support and applying said layer of heat sink material by a plating operation.
Claim 2
Dependent Claim
40 words
The method of claim 1 and further comprising: reducing the thickness of said layer of heat sink material to a predetermined thickness, and applying a layer of contact metallization to said heat sink material to facilitate the subsequent bonding thereof.
Claim 3
Dependent Claim
29 words
The method of claim 1 and further comprising: applying a layer of contact metallization between said layer of heat sink material and said one surface of said semiconductor substrate.
Claim 4
Dependent Claim
37 words
The method of claim 1 and further comprising: machining said semiconductor substrate to a predetermined thickness, and applying a layer of contact metallization before removing portions of said substrate to form an array of discrete semiconductor devices.
Claim 5
Dependent Claim
50 words
The method of claim 1 wherein said step of removing portions comprises: applying layers of photoresist material according to a predetermined mask, and etching away portions of said substrate in dependence upon said mask to form an array of discrete semiconductor devices extending from said layer of heat sink material.
Claim 6
Dependent Claim
31 words
The method of claim 1 and further comprising: applying a layer of passivating material to portions of said array of discrete semiconductor devices extending from said layer of heat sink material.
Claim 7
Independent Claim
136 words
The method of fabricating semiconductor devices comprising: a. applying a contact layer over one surface of a semiconductor body having a P-N junction, b. forming a layer of high conductivity heat sink material over said contact layer, said layer of heat sink material being of a predetermined thickness to provide selected heat dissipation for said P-N junction, c. forming a plurality of discrete spaced apart contacts over a surface of said semiconductor body opposite said layer of heat sink material, and d. removing portions of said semiconductor body between said spaced apart contacts to form an array of discrete active semiconductor devices extenDing from said heat sink material and terminating in said contacts, and thereafter e. dividing said layer of heat sink material to form a plurality of separate semiconductor devices attached to respective heat sinks.
Claim 8
Dependent Claim
24 words
The method of claim 8 further comprising: separating portions of said heat sink material to form a plurality of separate heat sinked semiconductor devices.
Claim 9
Dependent Claim
16 words
The method of claim 8 wherein said array of discrete active semiconductor devices comprise avalanche diodes.
Claim 10
Dependent Claim
33 words
The method of claim 8 wherein said contact layer applied over one surface of the semiconductor body comprises a multimetal layer to provide good ohmic contact with said layer of heat sink material.
Claim 11
Dependent Claim
20 words
The method of claim 8 wherein said layer of heat sink material is applied over said contact layer by electroplating.
Claim 12
Dependent Claim
36 words
The method of claim 8 wherein said discrete spaced apart contacts are formed over surface of said semiconductor body by applying a uniform layer of contact metal and etching away undesired portions of said contact metal.
Claim 13
Dependent Claim
23 words
The method of claim 8 wherein said portions of said semiconductor body are removed by etching away undesired portions defined by a mask.
Claim 14
Dependent Claim
41 words
The method of claim 8 and further comprising: reducing the thickness of said layer of heat sink material down to said predetermined thickness and applying a layer of contact metallization to enable bonding of said heat sink material to a support.
Claim 15
Independent Claim
132 words
The method of fabricating avalanche diodes with attached heat sinks comprising: a. forming a semiconductor slice having a P-N junction, b. applying a layer of contact metallization over the surface of said slice nearest said P-N junction, c. applying a layer of high conductivity metal over said contact metallization of a sufficient thickness to provide heat dissipation for said P-N junction, d. forming a plurality of spaced apart metal contacts over the surface of said slice opposite said layer of high conductivity metal, c. removing portions of said semiconductor slice between said metal contacts to form an array of discrete avalanche diodes extending from said layer of high conductivity metal, and f. dividing said layer of high conductivity metal to provide a plurality of avalanche diodes attached to individual heat sink members.
Claim 16
Dependent Claim
22 words
The method of claim 16 wherein said layer of contact metallization applied over the surface of said slice comprises a multimetal layer.
Claim 17
Dependent Claim
17 words
The method of claim 16 wherein said layer of high conductivity metal is applied by electroplating techniques.
Claim 18
Dependent Claim
30 words
The method of claim 16 and further comprising: applying a layer of contact metallization to a surface of said high conductivity metal layer to facilitate bonding to a support member.
Claim 19
Dependent Claim
33 words
The method of claim 16 wherein said layer of high conductivity metal is divided to provide an array of avalanche diodes having closely similar thermal resistances upon a single supporting heat sink member.
Claim 20
Dependent Claim
29 words
The method of claim 16 and further comprising: applying a layer of passivating material to said discrete avalanche diodes before the dividing of said layer of high conductivity metal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-12 | 1976-03-13 | 1976-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-12 | 1980-03-13 | 1980-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-12 | 1984-03-13 | 1984-09-12 | $7700.00 | Window Closed / Lapsed |