US4450471A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semi-conductor power device assembly and method of manufacture thereof
Assignee: ZF International UK Ltd
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Filing: 1981-06-12
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Granted: 1984-05-22
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Expires: 2001-06-12
Abstract
Abstract A heat spreader has a thin ceramic layer plasma sprayed onto its lower surface which may be chamfered. The upper surface of the spreader is then plated with a thin nickel or gold layer and a semi-conductor power device is soldered to the latter. The spreader is then secured via the ceramic layer to a base material serving as a heat sink by a layer of epoxy resin loaded with silver particles. The thin ceramic layer electrically insulates the spreader from the base material but enables heat conduction therebetween. The application of the plasma sprayed ceramic layer to the spreader is easy and economical to effect.
Inventors
- 👤 Felicitas Wellhoefer
- 👤 David W. Stacey, deceased
- 👤 legal representative by Lesley A. Stacey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:44
CPC Classifications
H; H10; H10W; H10W40/00; H10W40/10; H10W40/01; H10W40/03; H10W40/037; H10W40/20; H10W40/25; H10W40/255
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
89 words
In an assembly containing a semi-conductor power device and a base material heat sink, the improvement comprising: a heat spreader interposed between said power device and said base material; a ceramic, electrically insulating, heat conducting, layer spray-bonded to the bottom of the heat spreader; an electrically conducting and heat conducting bonding layer means for bonding the base material to the ceramic layer; a thin metallic plate layer bonded to the top of the heat spreader; and a solder layer bonding the metallic plate layer to the semi-conductor power device.
Claim 2
Dependent Claim
89 words
In an assembly containing a semi-conductor power device and a base material heat sink, the improvement comprising: a heat spreader interposed between said power device and said base material; a ceramic, electrically insulating, heat conducting, layer spray-bonded to the bottom of the heat spreader; an electrically conducting and heat conducting bonding layer means for bonding the base material to the ceramic layer; a thin metallic plate layer bonded to the top of the heat spreader; and a solder layer bonding the metallic plate layer to the semi-conductor power device.
Claim 3
Dependent Claim
36 words
The assembly according to claim 1, wherein the bonding layer by which the ceramic layer is bonded to the base material is spaced inwardly from a peripheral edge of the ceramic layer over a portion thereof.
Claim 4
Dependent Claim
36 words
The assembly according to claim 2, wherein said heat spreader has a base provided with chamfered edges which are spaced from said base material and said ceramic layer extends over said base including said chamfered edges.
Claim 5
Dependent Claim
53 words
The assembly according to claim 2, wherein said base material has a raised portion having a smaller surface area than the surface area of said ceramic layer, and wherein the bond is effected between said raised portion and said portion of said ceramic layer which is spaced inwardly from the peripheral portion thereof.
Claim 6
Dependent Claim
17 words
The assembly according to claim 1, wherein said bonding layer comprises a resin loaded with heat-conductive particles.
Claim 7
Dependent Claim
29 words
The assembly according to claim 1, wherein said bonding layer comprises a solder bonded to said base material and to a solderable metal layer applied to said ceramic layer.
Claim 8
Dependent Claim
15 words
The assembly according to claim 1, wherein said ceramic layer is a plasma sprayed layer.
Claim 9
Independent Claim
161 words
A method of manufacturing an assembly containing a semi-conductor power device and a base material heat sink having an improvement wherein: a heat spreader is interposed between said power device and said base material; a ceramic, electrically insulating, heat conducting, layer is spray-bonded to the bottom of the heat spreader; an electrically conducting and heat conducting bonding layer means bonds the base material to the ceramic layer; a thin metallic plate layer is bonded to the top of the heat spreader; and a solder layer bonds the metallic plate layer to the semi-conductor power device; said method comprising the non-sequential steps of: spraying the ceramic layer onto a bottom surface of the heat spreader; bonding the thin metallic plate layer to the top surface of the heat spreader; bonding the semi-conductor power device to the metallic layer by means of the solder layer; and bonding the base material heat sink to the bonded ceramic layer by means of a bonding layer.
Claim 10
Independent Claim
161 words
A method of manufacturing an assembly containing a semi-conductor power device and a base material heat sink having an improvement wherein: a heat spreader is interposed between said power device and said base material; a ceramic, electrically insulating, heat conducting, layer is spray-bonded to the bottom of the heat spreader; an electrically conducting and heat conducting bonding layer means bonds the base material to the ceramic layer; a thin metallic plate layer is bonded to the top of the heat spreader; and a solder layer bonds the metallic plate layer to the semi-conductor power device; said method comprising the non-sequential steps of: spraying the ceramic layer onto a bottom surface of the heat spreader; bonding the thin metallic plate layer to the top surface of the heat spreader; bonding the semi-conductor power device to the metallic layer by means of the solder layer; and bonding the base material heat sink to the bonded ceramic layer by means of a bonding layer.
Claim 11
Dependent Claim
43 words
The method according to claim 8, wherein surface portions of the base material and the heat spreader to be bonded together are flat, and the method further includes the step of clamping the heat spreader against a flat surface during the spraying step.
Claim 12
Dependent Claim
30 words
The method according to claim 8 or 9, for producing a plurality of assemblies, wherein the spraying step is effected on a plurality of heat spreaders disposed in close proximity.
References Cited (Backward Citations)
US3290564A
Cited
US4356505A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-05-22 | 1987-11-21 | 1988-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-22 | 1991-11-21 | 1992-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-22 | 1995-11-21 | 1996-05-22 | $7700.00 | Window Closed / Lapsed |