Silver electroplating compositions and methods for electroplating rough matt silver

Patent metadata

Field	Value
Publication number	US-11629426-B1
Application number	US-202217852825-A
Country	US
Kind code	B1
Filing date	Jun 29, 2022
Priority date	Jun 29, 2022
Publication date	Apr 18, 2023
Grant date	Apr 18, 2023

Abstract

Silver electroplating compositions deposit rough, matt silver having needle-like grain structures. The rough, matt, silver deposits enable good adhesion with dielectric materials, even in environments of high relative humidity.

First claim

What is claimed is:

1. A silver electroplating composition comprising silver ions, a conductivity compound and a compound having a formula:

wherein R 1 is hydrogen or C 1 -C 4 alkyl and R 2 is C 1 -C 4 alkyl or phenyl.

2. The silver electroplating composition of claim 1 , wherein the compound is selected from the group consisting of 6-(dibutylamino)-1,3,5-triazine-2,4-dithiol, 6-anilino-1,3,5-triazine-2,4-dithiol and mixtures thereof.

3. The silver electroplating composition of claim 1 , wherein the compound is in amounts of at least 1 ppm.

4. The silver electroplating composition of claim 1 , wherein the conductivity compound comprises potassium dihydrogen phosphate, potassium phosphate, sodium phosphate, ammonium phosphate, sodium nitrate, organic acids, inorganic acids or mixtures thereof.

5. The silver electroplating composition of claim 1 , further comprising a buffering agent.

6. The silver electroplating composition of claim 1 , further comprising a pH adjusting agent.

7. The silver electroplating composition of claim 1 , further comprising a silver complexing agent.

8. The silver electroplating composition of claim 1 , further comprising an organic solvent chosen from pyridine and pyridine compounds.

9. The silver electroplating composition of claim 8 , wherein the pyridine compound consists of 2-pyridinemethanol, 3-pyridinemethanol, 2-pyridineethanol, 3-pyridineethanol, and mixtures thereof.

10. The silver electroplating composition of claim 1 , wherein a pH of the silver electroplating composition is 6-14.

11. A method of electroplating rough, matt silver on a substrate comprising:
a) providing the substrate;
b) contacting the substrate with the silver electroplating composition of claim 1 ; and
c) applying an electric current to the silver electroplating composition and substrate to electroplate a rough, matt silver deposit on the substrate.

12. The method of claim 11 , wherein the rough, matt silver deposit comprises a Sa of 0.1-0.4 μm and an Sdr of 5-50%.

13. The method of claim 11 , wherein the rough, matt silver deposit has needle-like structures comprising a peak height of 1-4 μm and a peak base of 0.2-0.4 μm.

14. The method of claim 11 , wherein a current density is 10 ASD to 180 ASD.

Assignees

• Rohm And Has Electronic Mat Llc
• Rohm & Haas Elect Mat

Inventors

• Ting Fai Lung
• Wu Weigang

Classifications

• C25D7/12

  Semiconductors · CPC title

• C25D5/605 Primary

  Surface topography of the layers, e.g. rough, dendritic or nodular layers · CPC title

• C25D3/46 Primary

  of silver · CPC title

• C25D5/627

  Electroplating characterised by the visual appearance of the layers, e.g. colour, brightness or mat appearance · CPC title

• C25D5/18

  Electroplating using modulated, pulsed or reversing current · CPC title