Used for manufacturing Electroplating tank The material of the lining is determined by the properties of the electrolyte (such as corrosion resistance and temperature resistance). Commonly used materials include PVC, rigid (or flexible) polypropylene sheets, titanium plates, lead plates, and ceramics. Now, regarding electroplating tanks: What causes the gold plating layer to turn black?

　　Electroplating tank: What causes the gold plating layer to turn black?

　　1. Control of Electroplated Nickel Layer Thickness

　　The gold-plated layer on PCBs is typically very thin. Many surface issues with the gold plating can be traced back to poor performance of the nickel plating. Generally, if the nickel plating layer is too thin, it can cause the product’s surface to appear whitish or blackened. Therefore, this is the first item that engineering and technical personnel should check. Typically, a nickel plating thickness of around 5 μm is required to effectively eliminate the whitish and blackened appearance.

　　2. Condition of the nickel plating bath solution

　　If the nickel plating bath solution is not properly maintained over a long period and carbon treatment is not carried out in a timely manner, the nickel layer deposited will easily develop flaky crystals, leading to increased coating hardness and enhanced brittleness. In severe cases, this can result in discoloration of the coating, turning it black. Therefore, engineering and technical personnel must carefully inspect the condition of the plating bath solution on the production line, conduct comparative analyses, and promptly perform thorough carbon treatment to restore the solution’s activity and maintain the cleanliness of the electroplating bath.

　　3. Golden Cylinder Control

　　As long as the liquid medicine is properly filtered and replenished, the gold tank will exhibit better contamination levels and stability than the nickel tank. However, it’s essential to verify that the gold bottle supplement is added in sufficient and appropriate amounts, to ensure proper control of the liquid medicine’s pH value, and to check the status of the conductive salts. If these checks reveal no issues, use an AA analyzer to determine the impurity content in the solution and assess the overall condition of the liquid stored in the reservoir. Also, take a moment to inspect whether the filter cotton core in the gold tank hasn’t been replaced for an extended period.

　　Electroplating Tank: What are the solutions for blackening of the electroplating solution?

　　1. The pre-treatment of special electroplating products must be thoroughly clean and complete; regularly filter out any oils and rust. Otherwise, excessive buildup can cause the plating solution to turn black, significantly reducing its service life.

　　2. When necessary, two curing tanks are used for electroplating and oxidation. This approach not only resolves the issue of red and gray deposits but also extends the service life of the plating solution.

　　3. Try not to interrupt the production process or complete it in one go, as each heating of the electroplating solution causes molecules to escape, resulting in unnecessary waste.

　　4. It is crucial to strictly control each inspection point according to the standard operating procedures—especially the inspection point involving the heating of the plating solution. If the plating solution temperature is too high, it can lead to red-gray deposits; if it’s too low, the plating layer on the product may stick together or become thinner. Therefore, it’s essential to constantly monitor the temperature of the plating solution.

　　5. There’s a high probability that some small electroplating parts might fall into the plating solution tank, leading to the loss of active molecules. Therefore, it’s essential to retrieve them promptly.