Patent US62120A successfully refreshed from Google Patents.
Patent US2728790A successfully refreshed from Google Patents.
← Back to Patent Explorer
US4132813A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for producing solderable metallized layer on a semiconducting or insulating substrate

Assignee: Robert Bosch GmbH
•
Filing: 1976-10-22
•
Granted: 1979-01-02
•
Expires: 1996-10-22
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract The provision of a supplementary layer of nickel by an electroless process in order to provide solder wetting capability for a tempered aluminum-nickel metallization is made unnecessary by causing the layer of nickel deposited on an underlying aluminum metallization layer to have a thickness between 0.6 and 1.0 μm and by conducting the subsequent tempering operation between 400 and 480° C, preferably 475° C, for a period of between 10 and 20 minutes, preferably 15 minutes. In order to provide high transverse conductivity, the aluminum layer should have a thickness between 3 and 10 μm. The process is useful in the manufacture of semiconductor devices as well as for making electrical devices based on an insulating substrate.

Inventors

  • 👤 Gerhard Schaal

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 18:26
CPC Classifications
H; H10; H10W; H10W99/00; H10W20/00; H10W20/40; H10W20/41; H10W20/425

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 203 words
A method of manufacturing a solderable metallized layer of high transverse electrical conductivity on a substrate, in which heat-tempering of an aluminum layer is necessary to provide adequate mechanical and electrical contact thereof and a nickel layer is provided for solderability, comprising the steps of: applying to said substrate (1) an aluminum layer (7) of a thickness in the range of 3 to 10 μm; applying under vacuum on top of said aluminum layer (7), a layer of nickel (8) which provides the entire nickel content of the metallization and has a thickness in the range from 0.6 to 1.0 μm, the application of said nickel layer being performed without interruption of the vacuum established for the previous application of aluminum; performing the tempering of the aluminum layer necessary for improving its electrical contact capability by heating said substrate and said applied layers, after the deposition of all of said nickel layer, to a temperature in the range of 400 to 480° C. and then maintaining said substrate and said applied layers at such a temperature for a period of not more than 20 minutes, whereby the electrical contact of said aluminum layer is improved without impairing the solderability of said nickel layer.
Claim 2
Independent Claim 203 words
A method of manufacturing a solderable metallized layer of high transverse electrical conductivity on a substrate, in which heat-tempering of an aluminum layer is necessary to provide adequate mechanical and electrical contact thereof and a nickel layer is provided for solderability, comprising the steps of: applying to said substrate (1) an aluminum layer (7) of a thickness in the range of 3 to 10 μm; applying under vacuum on top of said aluminum layer (7), a layer of nickel (8) which provides the entire nickel content of the metallization and has a thickness in the range from 0.6 to 1.0 μm, the application of said nickel layer being performed without interruption of the vacuum established for the previous application of aluminum; performing the tempering of the aluminum layer necessary for improving its electrical contact capability by heating said substrate and said applied layers, after the deposition of all of said nickel layer, to a temperature in the range of 400 to 480° C. and then maintaining said substrate and said applied layers at such a temperature for a period of not more than 20 minutes, whereby the electrical contact of said aluminum layer is improved without impairing the solderability of said nickel layer.
Claim 3
Dependent Claim 25 words
A method as defined in claim 1, in which the period of maintaining said temperature in said tempering step is not less than 10 minutes.
Claim 4
Dependent Claim 29 words
A method as defined in claim 2, in which the tempering period has a duration of about 15 minutes and in which the tempering temperature is about 475° C.
Claim 5
Dependent Claim 29 words
A method as defined in claim 2, in which the tempering period has a duration of about 15 minutes and in which the tempering temperature is about 475° C.
Claim 6
Dependent Claim 18 words
A method as defined in claim 2, in which said substrate (1) is of a solid insulator material.
Claim 7
Dependent Claim 16 words
A method as defined in claim 5, in which said substrate is of a ceramic material.
Claim 8
Dependent Claim 38 words
A method as defined in claim 5, in which said insulator material is a solid material selected from the group consisting of glasses, oxides other than glasses, mixtures of oxides other than glasses, nitrides, and mixtures of nitrides.
Claim 9
Dependent Claim 39 words
A method as defined in claim 2, in which said substrate is of a solid semiconductor material and said tempering step after the deposition of the nickel layer improves the electrical contact of said aluminum layer with said substrate.
Claim 10
Dependent Claim 36 words
A method as defined in claim 2, in which said substrate is a component electrical apparatus made on a silicon blank covered at least partly with a protective surface layer consistingof at least one insulating material.
Claim 11
Dependent Claim 35 words
A method as defined in claim 9, in which said protective layer of said substrate at least part of which is a silicon oxide layer lying directly on the semiconductor body of said apparatus component.
Claim 12
Dependent Claim 25 words
A method as defined in claim 10, in which said surface layer of said substrate includes a nitride layer superimposed on said silicon oxide layer.
Claim 13
Dependent Claim 24 words
A method as defined in claim 11, in which said surface layer of said substrate includes a glass layer superimposed upon said nitride layer.
Claim 14
Dependent Claim 37 words
A method as defined in claim 1, in which said substrate is a component electrical apparatus made on a silicon blank covered at least partly with a protective surface layer consisting of at least one insulating material.

References Cited (Backward Citations)

US3479736A Cited
US3579375A Cited
US3633269A Cited
DE2143906A1 Cited
US3806361A Cited
US3922385A Cited
US3965279A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1982-01-01 1982-07-03 1983-01-02 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1986-01-01 1986-07-03 1987-01-02 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1990-01-01 1990-07-03 1991-01-02 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag