After adding water and sulfuric acid, we can proceed to the following step when we use acid tin plating brightener to prepare tank solution.
How to add Stannous Sulfate?
With constant stirring, we slowly sprinkle chemical pure stannous sulfate (the main salt) into the above mixture in calculated amounts while it is still hot, or if you want to play it safe, you can wrap the stannous sulfate in multiple layers of plastic saran wrap, and then suspend it in a tank and allow it to dissolve slowly and naturally with constant stirring.
What is the cause of the difficulty in dissolving stannous sulfate?
In the use of acid tin plating brightener in the actual production operation, sometimes stannous sulfate dissolution difficulties occur, this is because the dissolution speed of stannous sulfate is relatively slow, easy to agglomerate at the bottom of the plating tank. And we know that adding concentrated sulfuric acid will be exothermic, using this feature, you can slowly sprinkle the tin sulfate and constantly stirring, make sure that it is fast and fully dissolved. in the actual production operation, sometimes encountered stannous sulfate dissolution difficulties, this is because the dissolution speed of stannous sulfate is relatively slow, easy to agglomerate at the bottom of the plating tank. And we know that adding concentrated sulfuric acid will be exothermic, using this feature, you can slowly sprinkle the tin sulfate and constantly stirring, make sure that it is fast and fully dissolved.
What is the temperature and stirring time for dissolving stannous sulfate?
The temperature of the solution for dissolving stannous sulfate should be kept below 70°C. What should be done if the solution temperature is below this figure? It can be heated using an electric heating device. Generally speaking, we need to stir constantly for 4-6 hours to get all the tin sulfate to dissolve.
How can we tell if it has all dissolved?
It's very simple, you can directly look at the color of the aqueous solution, if it is milky white, but there is no sediment, it means that all dissolved. If the tin sulfate does not dissolve completely, it can be filtered directly into the plating bath using a 1μm activated carbon cartridge.
If you don't add brightener, you can only get the plating layer with coarse gray crystallization when plating. Bigely's acid tin plating brightener Sn-807 makes the surface of the product free of yellow spots and streaks, and the plating layer is clear and goes well.
If you need to purchase acid tin plating brightener, or you want to know more about the process knowledge, please feel free to contact us.
