US 12,325,927 B2
Complex waveform for electrolytic plating
Donald Desalvo, Jiangsu Province (CN); Ron Blake, Oxford, CT (US); Carmichael Gugliotti, Bristol, CT (US); William J. Decesare, Wolcott, CT (US); Richard A. Bellemare, Watertown, CT (US); James Watkowski, Middlebury, CT (US); and Ernest Long, Burlington, CT (US)
Assigned to MacDermid Enthone Inc., Waterbury, CT (US)
Appl. No. 18/568,465
Filed by MacDermid Enthone Inc., Waterbury, CT (US)
PCT Filed May 25, 2022, PCT No. PCT/US2022/030882
§ 371(c)(1), (2) Date Dec. 8, 2023,
PCT Pub. No. WO2022/271390, PCT Pub. Date Dec. 29, 2022.
Claims priority of provisional application 63/215,031, filed on Jun. 25, 2021.
Prior Publication US 2024/0271307 A1, Aug. 15, 2024
Int. Cl. C25D 5/18 (2006.01); C25D 3/38 (2006.01); C25D 5/02 (2006.01); C25D 7/00 (2006.01); C25D 7/12 (2006.01); H05K 3/42 (2006.01)
CPC C25D 5/18 (2013.01) [C25D 3/38 (2013.01); C25D 5/02 (2013.01); C25D 7/00 (2013.01); H05K 3/421 (2013.01); H05K 3/424 (2013.01); C25D 7/12 (2013.01)] 24 Claims
OG exemplary drawing
 
1. A method of plating a metal on an electronic substrate, wherein the electronic substrate comprises one or more features, wherein the one or more features comprise one or more through-holes in the electronic substrate, the method comprising the steps of:
a) preparing the electronic substrate to receive metal plating thereon;
b) bringing the electronic substrate and at least one counter electrode into contact with an electroplating solution comprising a source of metal ions of the metal to be plated;
c) electrically polarizing first and second sides of the electronic substrate to initiate metal plating thereon, wherein the electroplating solution plates the one or more through-holes using a plating cycle until metallization is complete;
wherein the plating cycle comprising the steps of, in order:
1) pulse plating for a first time period on a first side and a second side of the electronic substrate to cause metal to preferentially plate in the center of the one or more through-holes, wherein the metal merges together in the center of the one or more through-holes to form two opposing blind vias; and
2) direct plating for a second time period to fill the two opposing blind vias formed by pulse plating;
wherein the pulse plating step comprises applying an electrical current to electrodeposit metal from the electroplating solution to the first side and second side of the electronic substrate, wherein the electrical current is applied as a pulse plating cycle comprising a repeatable sequence, wherein the repeatable sequence comprises a set of pulse plating periods, each set of pulse plating periods including, in any order:
(i) at least a first forward pulse period;
(ii) at least a first reverse pulse period;
(iii) at least a second forward pulse period; and
(iv) at least one rest period,
wherein pulse breaks are interposed between at least one of the pulse plating periods in the set of pulse plating periods;
wherein the at least one rest period is longer in duration than each pulse break, wherein the at least one rest period on one side of the electronic substrate coincides with a forward pulse on the opposite side of the electronic substrate,
wherein the at least one rest period and the forward pulse have at least substantially the same duration.