PCB is an important electronic component, a support for electronic components, and a carrier for electrical connection of electronic components. In the process of PCB manufacturing, blackening will occur. What are the main reasons for the blackening of the gold plated circuit board
1. Electroplated nickel layer thickness control
Gold plating on gold plated circuit board is generally very thin, reflecting that many problems with gold plating surfaces are caused by poor performance of electroplated nickel. Generally, the thin nickel plating layer will cause the appearance of the product to be whitish and black. Therefore, this is the first choice for the factory engineering technicians to check the project. It is generally necessary to plate the thickness of the nickel layer to about 5 UM.
2. Electroplated nickel cylinder syrup condition
If the nickel cylinder syrup is not well maintained for a long time, and the carbon treatment is not carried out in time, the nickel layer is electroplated by gold plated circuit board to facilitate the formation of flaky crystals, and the hardness of the coating is increased and the brittleness is enhanced. Severe black plating problems can occur. This is a lot of people who tend to ignore control points. It is also often an important cause of problems. Therefore, please carefully check the syrup status of your factory production line, carry out comparative analysis, and carry out thorough carbon treatment in time to restore the syrup activity and the plating solution clean.
3. Gold cylinder control
Now I only talk about the gold cylinder control. Generally, if you only keep good syrup filtration and replenishment, the gold cylinder will be less polluted and stable than the nickel cylinder. But you need to pay attention to check if the following aspects are good:
(1) Is the gold cylinder supplement added enough and excessive?
(2) What is the control of the PH value of the syrup?
(3) What is the status of conductive salt?
If there is no problem with the inspection results, analyze the analysis of the impurity content in the solution with an AA machine. Guarantee gold tank syrup status. Finally, don't forget to check the gold cylinder filter cotton core.