# US 2019/0314937 A1 · Sn Whisker Growth Mitigation Using NiO Sublayers

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- Number: US 2019/0314937 A1
- Document ID: US20190314937A1
- Status: Published application
- Kind: A1
- Application number: 16/381,445
- Filed: 2019-04-11
- Published: 2019-10-17
- Earliest claimed: 2018-04-11
- Assignees: The University of Toledo
- Applicants: The University of Toledo
- Inventors: Vamsi Borra; Daniel G. Georgiev; Srikanth Itapu
- Web page: https://patentgrep.com/patent/US20190314937A1

## CPC

- B23K 35/262: {Sn as the principal constituent}
- B23K 1/0016: {Soldering of electronic components}
- B23K 3/08: Auxiliary devices therefor
- B23K 26/0006: {taking account of the properties of the material involved (B23K26/32, B23K26/40 take precedence)}
- B23K 26/342: Build-up welding
- H05K 1/09: Use of materials for the {conductive, e.g. } metallic pattern
- H05K 3/24: Reinforcing of the conductive pattern {(by solder coating H05K3/3465)}
- H10W 70/662: {Semiconductor materials}
- H10W 72/00: Interconnections or connectors in packages
- B23K 2101/40: Semiconductor devices
- B23K 2101/42: Printed circuits
- B23K 2103/172: {wherein at least one of the layers is non-metallic}
- B23K 2103/26: {Alloys of Nickel and Cobalt and Chromium}
- B23K 2103/56: {being semiconducting}
- H05K 3/146: {By vapour deposition}
- H05K 3/16: by cathodic sputtering
- H05K 2201/0317: Thin film conductor layer; Thin film passive component
- H05K 2201/0326: Inorganic, non-metallic conductor, e.g. indium-tin oxide [ITO]
- H05K 2201/0338: Layered conductor, e.g. layered metal substrate, layered finish layer or layered thin film adhesion layer
- H05K 2201/0391: Using different types of conductors
- H05K 2201/0769: Anti metal-migration, e.g. avoiding tin whisker growth
- B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

Semiconductor layers useable for minimizing or preventing the growth of metal whiskers, as well as devices and methods utilizing the same and kits for making the same, are described.

## Claims

### Claim 1

An electronic device comprising:
a substrate;
a first metal layer on the substrate;
a semiconductor layer comprising NiO on the first metal layer; and
a second metal layer on the semiconductor layer.

### Claim 2 (depends on 1)

The electronic device of claim 1, wherein the semiconductor layer is a uniform, continuous layer.

### Claim 3 (depends on 1)

The electronic device of claim 1, wherein the semiconductor layer fully covers a surface of the first metal layer.

### Claim 4 (depends on 1)

The electronic device of claim 1, wherein the semiconductor layer consists essentially of NiO.

### Claim 5 (depends on 1)

The electronic device of claim 1, wherein the semiconductor layer has a thickness ranging from about 20 nm to about 500 nm.

### Claim 6 (depends on 1)

The electronic device of claim 1, wherein the semiconductor layer has a thickness ranging from about 50 nm to about 200 nm.

### Claim 7 (depends on 1)

The electronic device of claim 1, wherein the semiconductor layer has a thickness of about 100 nm.

### Claim 8 (depends on 1)

The electronic device of claim 1, wherein the first or second metal layer comprises Sn.

### Claim 9 (depends on 1)

The electronic device of claim 1, wherein the first or second metal layer comprises Cu.

### Claim 10 (depends on 1)

The electronic device of claim 1, wherein the first or second metal layer comprises Zn.

### Claim 11 (depends on 1)

The electronic device of claim 1, wherein the first or second metal layer comprises Cd, Al, Au, or Ag.

### Claim 12 (depends on 1)

The electronic device of claim 1, wherein the second metal layer is substantially free of whiskers.

### Claim 13 (depends on 1)

The electronic device of claim 1, wherein the electronic device is a printed circuit board or an integrated circuit.

### Claim 14 (depends on 1)

The electronic device of claim 1, wherein the substrate comprises glass, silicon, or plastic.

### Claim 15 (depends on 1)

The electronic device of claim 1, wherein the second metal layer is directly on the NiO layer.

### Claim 16 (depends on 1)

The electronic device of claim 1, wherein the semiconductor layer is directly on the first metal layer, and the first metal layer is not Ni.

### Claim 17 (depends on 1)

The electronic device of claim 1, wherein the NiO comprises a dopant.

### Claim 18

An electronic device comprising:
a substrate;
a semiconductor layer comprising NiO directly on the substrate; and
a metal layer directly on the semiconductor layer.

### Claim 19 (depends on 18)

The electronic device of claim 18, wherein the semiconductor layer is a uniform, continuous layer.

### Claim 20 (depends on 18)

The electronic device of claim 18, wherein the semiconductor layer fully covers a surface of the substrate.

### Claim 21 (depends on 18)

The electronic device of claim 18, wherein the semiconductor layer consists essentially of NiO.

### Claim 22 (depends on 18)

The electronic device of claim 18, wherein the semiconductor layer has a thickness ranging from about 20 nm to about 500 nm.

### Claim 23 (depends on 18)

The electronic device of claim 18, wherein the semiconductor layer has a thickness ranging from about 50 nm to about 200 nm.

### Claim 24 (depends on 18)

The electronic device of claim 18, wherein the semiconductor layer has a thickness of about 100 nm.

### Claim 25 (depends on 18)

The electronic device of claim 18, wherein the metal layer comprises Sn, Cu, Zn, Cd, Ag, or Au.

### Claim 26 (depends on 18)

The electronic device of claim 18, wherein the substrate comprises glass, silicon, or plastic.

### Claim 27 (depends on 18)

The electronic device of claim 18, wherein the metal layer is substantially free of whiskers.

### Claim 28 (depends on 18)

The electronic device of claim 18, wherein the electronic device is a printed circuit board or an integrated circuit.

### Claim 29 (depends on 18)

The electronic device of claim 18, wherein the NiO comprises a dopant.

### Claim 30

A method for making an electronic device, the method comprising:
depositing a semiconductor layer comprising NiO on a substrate; and
depositing a metal layer on the semiconductor layer;
wherein the semiconductor layer substantially prevents the growth of whiskers on the metal layer.

### Claim 31 (depends on 28)

The method of claim 28, wherein the metal layer comprises Sn, Cu, Zn, Cd, Al, Au, or Ag.

### Claim 32 (depends on 28)

The method of claim 28, wherein the substrate comprises glass, silicon, or plastic.

### Claim 33

A kit comprising:
a first container housing a solder comprising Sn; and
a second container housing a source of nickel and a solution.