ACID ELECTROLYTE FOR SILVERING Russian patent published in 2014 - IPC C25D3/46 

FIELD: chemistry.

SUBSTANCE: acid electrolyte for silvering contains silver nitrate, used as a soluble compound, sulphamic acid and thiourea, used as reagents, providing the electrolyte stability, structure-forming additives in the form of gelatin, a non-ionogenic surface-active substance and one or several types of products from mercapto compounds, and it contains the said components in a water solution, which has pH from 0 to 3, with the following ratio, g/l: silver nitrate (by Ag) 10-20, sulphamic acid 10-20, thiourea 130-150, gelatin 0.5-1.5, non-ionogenic surface-active substance 1-3, one or several types of products from mercapto compounds 0.1-1.0.

EFFECT: creation of the acid silvering electrolyte, providing precipitation on printed circuit boards of a dense homogeneous fine crystalline coating, which has no external defects and does not cause destruction and detachment of an organic photoresist film in the process of the coating application.

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