Patent US1584518A successfully refreshed from Google Patents.
US6133071A
Expired / Lapsed
US
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Semiconductor device with plate heat sink free from cracks due to thermal stress and process for assembling it with package
Assignee: NEC Compound Semiconductor Devices Ltd
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Filing: 1998-10-15
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Granted: 2000-10-17
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Expires: 2018-10-15
Abstract
Abstract A compound semiconductor pellet for a high electron mobility transistor is bonded to a metal plate heat sink of gold, and the metal plate heat sink is soldered to a package, wherein the metal plate heat sink is subjected to an orientation under application of heat before the soldering so as to cure warp of the compound semiconductor pellet, thereby decreasing the thermal stress due to the heat during the soldering.
Inventors
- 👤 Keiji Nagai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:59
CPC Classifications
H; H10; H10W; H10W40/00; H10W40/20; H10W40/25; H10W40/255; H10D; H10D62/00; H10D62/10; H10D62/117; H10W40/258; H10W72/00; H10W72/30
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
153 words
A process for assembling a plate heat sink device with a substrate, comprising, the steps of: a) preparing a plate heat sink device including a semiconductor pellet and a metal plate heat sink bonded to a first major surface of said semiconductor pellet and warped so as to have a radius of curvature of a first value; b) treating said plate heat sink device with heat so as to orient crystal grains of said metal plate heat sink to a predetermined plane, thereby increasing said radius of curvature from said first value to a second value; and c) bonding said plate heat sink device to a substrate under application of heat so as to keep said radius of curvature greater than a third value, said third value defined as being the radius of curvature resulting from warpage of said plate heat sink device when the bonding is carried out without said step b).
Claim 2
Dependent Claim
153 words
A process for assembling a plate heat sink device with a substrate, comprising, the steps of: a) preparing a plate heat sink device including a semiconductor pellet and a metal plate heat sink bonded to a first major surface of said semiconductor pellet and warped so as to have a radius of curvature of a first value; b) treating said plate heat sink device with heat so as to orient crystal grains of said metal plate heat sink to a predetermined plane, thereby increasing said radius of curvature from said first value to a second value; and c) bonding said plate heat sink device to a substrate under application of heat so as to keep said radius of curvature greater than a third value, said third value defined as being the radius of curvature resulting from warpage of said plate heat sink device when the bonding is carried out without said step b).
Claim 3
Dependent Claim
24 words
The process as set forth in claim 1, in which said plate heat sink device is bonded to said substrate by using a soldering.
Claim 4
Dependent Claim
23 words
The process as set forth in claim 2, in which soldering material used in said c) is melted around 300 degrees in centigrade.
Claim 5
Dependent Claim
55 words
The process as set forth in claim 2, in which said semiconductor pellet and said metal plate heat sink are mainly formed of gallium arsenide and gold, respectively, and said gold is subjected to the orientation under the conditions at 200 degrees to 300 degrees in centigrade for about 30 minutes in said step b).
Claim 6
Dependent Claim
26 words
The process as set forth in claim 4, in which said orientation is changed from (111) plane to a combination of (111) plane and (200) plane.
Claim 7
Dependent Claim
64 words
The process as set forth in claim 1, in which a center for said radius of curvature is on the opposite side to said semiconductor pellet with respect to said metal plate heat sink in said step a) and said step b), and said center is moved to the same s ide as said semiconductor pellet with respect to said metal plate heat sink.
Claim 8
Dependent Claim
55 words
The process as set forth in claim 1, in which a center for said radius of curvature is on the opposite side to said semiconductor pellet with respect to said metal plate heat sink in said step a) and said step b), and said plate heat sink device becomes substantially flat in said step c).
Claim 9
Dependent Claim
45 words
The process as set forth in claim 1, in which a center for said radius of curvature is on the opposite side to said semiconductor pellet with respect to said metal plate heat sink in said step a), said step b) and said step c).
Claim 10
Dependent Claim
65 words
The process as set forth in claim 4, in which said semiconductor pellet and said metal heat sink are about 30 microns to about 50 microns thick and 10 microns to 30 microns thick, respectively, and said radius of curvature is changed from 10 cm in said step a) through 20 cm in said step b) to more than 20 cm in said step c).
Claim 11
Dependent Claim
62 words
The process as set forth in claim 9, in which said semiconductor pellet has a the gallium arsenide layer of 30 microns to 50 microns thick and an indium gallium arsenide layer of 10 nanometers to 15 nanometers thick epitaxially grown on a major surface of said gallium arsenide opposite to said major surface where said metal plate heat sink is bonded.
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) | 2003-10-17 | 2004-04-17 | 2004-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-10-17 | 2008-04-17 | 2008-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-10-17 | 2012-04-17 | 2012-10-17 | $7700.00 | Window Closed / Lapsed |