	US 12,442,099 B2
	Electroplating solutions
Alan Boardman, Reading (GB)
Assigned to Johnson Matthey Public Limited Company, London (GB)
Appl. No. 18/250,487
Filed by JOHNSON MATTHEY PUBLIC LIMITED COMPANY, London (GB)
PCT Filed Dec. 16, 2021, PCT No. PCT/GB2021/053322 § 371(c)(1), (2) Date Apr. 25, 2023, PCT Pub. No. WO2022/129916, PCT Pub. Date Jun. 23, 2022.
Claims priority of application No. 2020071 (GB), filed on Dec. 18, 2020.
Prior Publication US 2023/0407507 A1, Dec. 21, 2023
Int. Cl. C25D 3/52 (2006.01); C25D 3/50 (2006.01)

CPC C25D 3/52 (2013.01) [C25D 3/50 (2013.01)]

17 Claims

1. An electroplating bath comprising a cathode and an anode which are both at least partially submerged in an electrolyte, wherein the electrolyte is an aqueous electroplating solution comprising

[Pt(NH₃)₄]²⁺ ions; and organic anions selected from the group consisting of bicarbonate, carbonate, or a mixture thereof;

wherein the molar ratio of Pt: (bicarbonate+carbonate) is approximately 1:2; and

wherein the following species, if present, are present in the following amounts:

alkali metals in an amount of less than 5 g/L;

compounds comprising phosphorus in an amount of less than 5 g/L;

compounds comprising boron in an amount of less than 5 g/L.