Measurement and correction of macro-stress in electrodeposits

Internally-stressed electrodeposits can result in defects. In the case of compressive stress, coatings can lift or blister, while tensile stress leads to deposit cracking. By means of in-situ stress measurement during the actual deposition, it is possible to ensure that stress levels are held within set limits. Three different techniques were compared, of which the MSM 200 technique, developed at FEM Schwaebisch Gmuend, gave the best results. By way of example, deposition of nickel from a Watts bath is demonstrated. By dosing of the solution with saccharin and butynediol, consistently stress-free deposits could be formed.