With the integration of integrated circuits is getting higher, the pin of the integrated circuit is also getting denser. It’s difficult for vertical tin plating process to smooth the fine solder pads. So we need the gold-plated tungsten alloy board to solve this problem.

It would be more durable if the circuit board is made of gold-plated tungsten alloy. The corrosion resistance of other metals is not as good as gold, and other metal will gradually be oxidized, slowly turn black. Even if the process is good, once it lost the surface bright, the ornamental price would be greatly reduced. Gold plating process must be very strict, especially the gold-plated process of the circuit board. According to the gold plating process characteristics, it can be divided into two types: no cyanide gold plating and cyanide gold-plating. Cyanide can be divided into high cyanide and low cyanide bath. Cyanide free plating bath was often applied to sulfite gold plating bath.

 

 

Circuit board gilding process introduction:

 

Purpose and function: gold, a precious metal, has good weldability, oxidation resistance, corrosion resistance, small contact resistance, good wear resistance.

 

At present, the gold-plated circuit board is mainly made of citric acid gold bath. It is widely used because of its simple maintenance and easy operation;

 

The gold content of water gold is controlled at about 1 grams / liter. pH value is about 4.5. Temperature is 35 degrees, proportion is about 14 Baume. Current density is about 1 ASD.

 

The main adding drugs: acid salt and basic salt with adjusting the pH value, conductive salt that regulates the proportion, gild additive and gold salt, etc.

 

In order to protect the gold tank, a trough of citric acid should be added, which can effectively reduce the pollution and keep the gold tank stable.

 

After plating the gold board, the pure water is used as the recovery water. It also can be used to supplement the level of gold cylinder evaporation changes.

 

The gold cylinder should use platinized titanium mesh as the anode. Generally speaking, stainless steel 316 is easy to be dissolved, which causes nickel, iron, chromium and other metal polluting gold cylinder, and defects such as blushing, blackening, etc.

 

Organic contamination of gold tanks should be continuously filtered with carbon core and supplemented with a suitable amount of gold plating additives.