| This additive is a light yellow or brown liquid developed by combining the merits of Sn-salt and Ni-Salt bath. It can stabilize Sn+2 ion in the solution and has nice uniformity and reproducibility in color. The storage time of this additive is in one year, when kept in a place avoiding of light. |
| 1. Bath Composition (For make-up): |
| |
SnSO4
NiSO4·6H2O
BY-C11B
H2SO4
Deionized Water
|
10-15g/L
8-12g/L
50g/L
15-20g/L
balance |
| 2. Processing Parameters: |
| |
Voltage
Temperature
pH value
Time
|
15-20V
20±5
0.8-1.2
30sec-15min |
| 3. Bath Maintenance: |
|
(1) Analyze the pH value and contents of free H2SO4 and SnSO4 daily, recompensed SnSO4, NiSO4 and H2SO4 in accordance with processing requirement. The compensation ratio between BY-C11B and SnSO4 is 1:1.
(2) Add purified water slowly with agitation, so as to prevent the local hydrolysis of SnSO4 which may cause the bath solution becoming turbid.
(3) After long period of production, there will be white sediment formed in the bottom of the tank that should be cleaned by filtration or decantation. |
