What does it mean that the precipitation does not appear during electroless plating, or the precipitation is incomplete?

The electroless plating solution used for plastic plating is mostly chemical copper plating, The commonly used chemical copper plating solution formula is:

Copper sulfate 79/L potassium sodium tartrate 259/L sodium hydroxide 59/L nickel chloride l9/L sodium carbonate 29/L formaldehyde l5mL/L pH value 12.5 In electroless copper plating, pH value and formaldehyde content are relative to the solution The deposition rate of slab has a greater impact,

If the pH value is lower than 12 and the formaldehyde content is lower than 1mL/L, the copper deposition may be interrupted or incomplete.

Of course, chemical nickel plating is also useful. No matter which process is used, it is possible to encounter incomplete deposition in actual production. What is the reason?

First, check the roughness to see if the surface of the product is fully wetted. If the coarsening is sufficient, check whether the activation is active, find out the problems that affect sensitization and activation, and eliminate them. If silver nitrate is used as the activation solution, you can check whether the surface color of the plastic workpiece is uniform light brown. If the color is not uniform, the problem lies in the process before activation; if the color is uniform, check the copper sinking solution.

When using colloidal palladium for activation, if it fails to deposit, you can dissolve it again and deposit again. If it is still incomplete, there may be a problem with the reaction ability of the electroless plating solution. However, some plastics are very difficult to roughen or the roughened surface is not suitable for adsorption solution, and the deposition will be incomplete. At this time, we must find a way to solve the roughening problem, and do not blindly replace the activation solution or electroless plating.

When colloidal palladium has strong activity, metal coatings can be deposited on poorly roughened surfaces, but its bonding force is very poor, so care must be taken to ensure the quality of roughening.