De ce? PCB electroplating gold layer turn black？

1. Potion status of electroplated nickel tank

Still have to talk about the nickel tank. If the nickel tank potion is not well maintained for a long time, and the carbon treatment is not carried out in time, the nickel layer after electroplating will easily produce flaky crystals, the hardness of the plating layer will increase, and the brittleness of the coating will increase. In severe cases, blackening of the coating will occur. This is because many people tend to overlook the key points of control. It is also often an important cause of problems. Therefore, please carefully check the potion status of your factory’s production line, conduct comparative analysis, and conduct thorough carbon treatment in time to restore potion activity and clean the electroplating solution.

2. Thickness control of electroplated nickel layer

Everyone must be talking about the blackening of the electroplated gold layer, how can it be the thickness of the electroplated nickel layer. In fact, the PCB plating gold layer is generally very thin, reflecting that many of the problems on the surface of the plating gold are caused by the poor performance of the electroplating nickel. Generally, the thinning of the electroplated nickel layer will cause the appearance of the product to be whitish and black. Therefore, this is the first choice for factory engineers and technicians to check. Generally, the thickness of the nickel layer needs to be electroplated to about 5 um to be sufficient.

3. Gold cylinder control

Acum vine vorba de controlul cilindrului de aur. În general, atâta timp cât mențineți o filtrare și o completare bună a poțiunii, poluarea și stabilitatea cilindrului de aur vor fi mai bune decât cele ale cilindrului de nichel. Dar trebuie să acordați atenție pentru a verifica dacă următoarele aspecte sunt bune:

(1) Are the supplements of the golden cylinder sufficient and excessive?

(2) How is the PH value of the potion controlled? (3) How about the conductive salt?

Dacă nu există nicio problemă cu rezultatul inspecției, utilizați aparatul AA pentru a analiza conținutul de impurități din soluție. Garantați starea poțiunii rezervorului de aur. În cele din urmă, nu uitați să verificați dacă miezul filtrului auriu al cilindrului nu a fost înlocuit de mult timp.