Patent US4810672A successfully refreshed from Google Patents.
US4810672A
Expired / Lapsed
US
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Method of securing electronic components to a substrate
Assignee: EUPEC GmbH
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Filing: 1987-03-25
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Granted: 1989-03-07
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Expires: 2007-03-25
Abstract
Abstract In order to secure electronic components, and particularly large-area power semiconductors, to a substrate, first a paste formed of metal powder and a solvent is applied in the form of a layer to a contacting layer of the component and/or a contact surface of the substrate. The layer of paste is then dried. When the paste has dried, the component is placed onto the substrate, whereupon the entire arrangement is heated to a relatively low sintering temperature preferably between 180° C. and 250° C., and with simultaneous application of a mechanical pressure of at least 900 N/cm 2 . A connection which is thus achieved by such a pressure sintering at relatively low sintering temperatures is particularly suitable for securing power semiconductors produced in MOS-technology to a substrate.
Inventors
- 👤 Herbert Schwarzbauer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:43
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W72/00; H10W72/30; H10W72/01; H10W72/013; H10W72/01365; H10W72/071; H10W72/073; H10W72/07311; H10W72/07331; H10W72/07336; H10W72/321; H10W72/325; H10W72/351; H10W72/352; Y; Y10; Y10S; Y10S148/00; Y10S148/012; Y10S148/054
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
105 words
A method of securing an electronic component having a contacting layer to a contacting surface of a substrate by pressure sintering, comprising steps of: applying a layer of a paste formed of metal powder and a solvent onto at least one of said contacting layers of the component and the contacting surface of the substrate; fully drying the applied paste; placing the component onto the substrate to form an assembly after the applied paste is fully dried; and heating the assembly to a sintering temperature with simultaneous application of a mechanical pressure of at least 900 N/cm 2 so as to perform said pressure sintering.
Claim 2
Independent Claim
105 words
A method of securing an electronic component having a contacting layer to a contacting surface of a substrate by pressure sintering, comprising steps of: applying a layer of a paste formed of metal powder and a solvent onto at least one of said contacting layers of the component and the contacting surface of the substrate; fully drying the applied paste; placing the component onto the substrate to form an assembly after the applied paste is fully dried; and heating the assembly to a sintering temperature with simultaneous application of a mechanical pressure of at least 900 N/cm 2 so as to perform said pressure sintering.
Claim 3
Dependent Claim
19 words
A method according to claim 1 wherein a powder of a noble metal is used as said metal powder.
Claim 4
Dependent Claim
20 words
A method according to claim 1 wherein a powder of a noble metal alloy is used as said metal powder.
Claim 5
Dependent Claim
15 words
A method according to claim 2 wherein silver powder is used as said metal powder.
Claim 6
Dependent Claim
19 words
A method according to claim 3 wherein a powder of a silver alloy is used as said metal powder.
Claim 7
Dependent Claim
20 words
A method according to claim 1 wherein said mechanical pressure is at least 1000 N/cm 2 during the pressure sintering.
Claim 8
Dependent Claim
20 words
A method according to claim 1 wherein said mechanical pressure is at least 1500 N/cm 2 during the pressure sintering.
Claim 9
Dependent Claim
26 words
A method according to claim 1 wherein said mechanical pressure corresponds at least to a given operating pressure of the pressure-contacted component during said pressure sintering.
Claim 10
Dependent Claim
38 words
A method according to claim 1 wherein prior to the pressure sintering, the component and the substrate are heated in pressure-free fashion to a temperature which is below the sintering temperature, and which is at least 100° C.
Claim 11
Dependent Claim
31 words
A method according to claim 9 wherein the component and the substrate are heated in pressure-free fashion to a temperature which corresponds approximately to a given operating temperature of the component.
Claim 12
Dependent Claim
22 words
A method according to claim 1 wherein the pressure sintering is carried out at a sintering temperature of at least 150° C.
Claim 13
Dependent Claim
24 words
A method according to claim 1 wherein the pressure sintering is carried out at a sintering temperature of between 180° C. and 250° C.
Claim 14
Dependent Claim
25 words
A method according to claim 1 wherein the pressure sintering is carried out in a press in which heated rams are applied to the assembly.
Claim 15
Dependent Claim
23 words
A method according to claim 1 wherein during the pressure sintering a top of the component is protected by a deformable intermediate layer.
Claim 16
Dependent Claim
33 words
A method according to claim 14 wherein during the pressure sintering a second intermediate layer formed of a hard material which has a low heat expansion coefficient is arranged above the intermediate layer.
Claim 17
Dependent Claim
16 words
A method according to claim 1 wherein the pressure sintering is followed by a pressure-free re-sintering.
Claim 18
Dependent Claim
33 words
A method according to claim 16 wherein sintering times of approximately one minute are selected for the pressure sintering, and sintering times in a range of several minutes are selected for the re-sintering.
Claim 19
Dependent Claim
15 words
A method according to claim 1 wherein the electronic component is a large-area power thyristor.
Claim 20
Dependent Claim
22 words
A method according to claim 18 wherein said substrate is molybdenum, said contacting surface comprises silver, and said contacting layer comprises silver.
Claim 21
Independent Claim
118 words
A method of securing a semiconductor wafer having an electrically conductive contacting layer to an electrically conductive contacting surface of a substrate by pressure sintering, comprising steps of: applying a layer of a paste formed of metal powder and a solvent onto at least one of said contacting layer of the wafer and the contacting surface of the substrate; substantially completely drying the applied paste to fully drive out the solvent; placing the wafer onto the substrate after the applied paste is substantially fully dried to form an assembly; and heating the assembly to a sintering temperature and applying a mechanical pressure of at least 900 N/cm 2 during the heating so as to perform said pressure sintering.
Claim 22
Independent Claim
118 words
A method of securing a semiconductor wafer having an electrically conductive contacting layer to an electrically conductive contacting surface of a substrate by pressure sintering, comprising steps of: applying a layer of a paste formed of metal powder and a solvent onto at least one of said contacting layer of the wafer and the contacting surface of the substrate; substantially completely drying the applied paste to fully drive out the solvent; placing the wafer onto the substrate after the applied paste is substantially fully dried to form an assembly; and heating the assembly to a sintering temperature and applying a mechanical pressure of at least 900 N/cm 2 during the heating so as to perform said pressure sintering.
Claim 23
Dependent Claim
15 words
A method according to claim 20 wherein said semiconductor wafer comprises a large-area power semiconductor.
Claim 24
Dependent Claim
15 words
A method according to claim 20 wherein the sintering temperature is less than 250° C.
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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) | 1992-03-06 | 1992-09-05 | 1993-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-06 | 1996-09-05 | 1997-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-06 | 2000-09-05 | 2001-03-07 | $7700.00 | Window Closed / Lapsed |