Description
Stress Characteristics
Compressive Stress– When the resist is outward. Tensile Stress– When the plated surface is outward.
Test Strip | Tensile Stress | Compressive Stress | Range, PSI | Composition |
1194 | Yes | Yes | 1,500 – 145,000 | Copper-Iron Alloy |
270NI | Yes | Yes | 200 – 60,000 | Pure Nickel |
Plating Procedure
Best results are obtained with a test set up similar to the above photograph. Anodes should be located at least three inches away from the Test Strip and should be positioned in a parallel plane with the Test Strip. Electrical contact should be made at the top of the Test Strip where there is a void in the masking material. The Test Strip should be immersed until only about 1″ remains above the solution level.
The plating current density should be adjusted with a given electrolyte so as not to cause deposit burning at the Test Strip’s tips, yet sufficient enough to conduct a rapid test. Preferably, the current density should be maintained at the approximate value at which the bath is normally worked.
NOTE: During plating a test strip is exposed to a uniform current density along the legs of the strip. The plating test should be continued until the test strip legs deflect up to 20 units and with a target thickness that does not exceed approximately 100 microinches for the most accurate results. Very low stress may show only 1-2 units.
Test Strip and Anode Considerations
Metallic Deposit | Test Strip | Anodes* |
Cadmium | 1194 | Cadmium |
Chromium | 270NI | Lead |
Cobalt | 1194 | Cobalt |
Copper | 1194 | Copper |
Gold | 270NI | Platinum Coated Titanium |
Nickel | 1194, 270NI | Nickel |
Palladium | 1194NI | Platinum Coated Titanium |
Platinum | 270NI | Platinum |
Rhodium | 270NI | Platinum Coated Titanium |
Silver | 1194 | Silver |
Tin | 1194 | Tin |
Zinc | 1194 | Zinc |
*Two are required, similar in composition, shape and size. Two Anodes 2 3/8″ (61mm) x 2 3/8″ (61mm) (Can be purchased from Kocour Company).
Note: For Electroless Nickel activation is not required for Chemically induced metallic deposition.