01 What are the aliases of gold plating and sinking gold?
Gold plating: hard gold, electric gold
Immersion gold: soft gold, chemical gold
02 The origin of the alias
Gold plating: through electroplating, the gold particles are attached to the board, so it is called electro-gold, because of its strong adhesion, it is also called hard gold, and the gold fingers of the memory stick are hard gold, which is wear-resistant.
Immersion gold: Through chemical reactions, gold particles crystallize and attach to the pads of the PCB board. Because of weak adhesion, it is also called soft gold.
03 The impact of gold plating and immersion gold on the patch
Gold plating: Do it before the solder mask, the green oil may not be cleaned cleanly, and it is not easy to tin. Immersion gold: After doing the solder mask, the patch is easy to tin.
04 Different processes and procedures
Gold plating: Do this process before solder masking, because gold plating requires two electrodes, one is the PCB board, and the other is the cylinder tank. If the PCB board is finished with solder masking, it will not be able to conduct electricity, and it will not be able to pass through the gold.
Immersion gold: After the solder mask is done, like immersion tin, chemical methods, gold will be attached to the place where there is copper leakage.
05 The impact of Zhenjin and immersion gold on electrical appliances
Gold plating: Before gold plating, a layer of nickel needs to be plated, and then a layer of gold is plated. The metal layer is copper-nickel-gold, because nickel is magnetic and has an effect on shielding electromagnetic waves.
Immersion gold: Immersion gold directly on the copper skin, the metal layer is copper gold, no nickel, no magnetic shielding.
06 Identification of gold plating and immersion gold
The gold plating process is magnetic because it contains nickel. When identifying gold plating or immersion gold, you can use a magnet to attract the PCB board. If it is attractive, it is gold plating, and if it is not attractive, it is immersion gold. In addition, the color is also different. The immersion gold is golden yellow. Because the gold surface is large, the gold plating is generally very thin, which is more than white. Of course, there are also thick plating, which is also golden yellow. At this time, it is difficult to distinguish the pads.
Pit avoidance guide
Flash Gold
The word flash gold comes from the English Flash, which means fast gold plating. In fact, it is the "pre-gold plating" process of electroplating hard gold. It uses a large current and a liquid bath with a thicker gold content to form on the surface of the nickel layer first. A finer density but thinner gold plating layer facilitates the subsequent electroplating of gold-nickel or gold-cobalt alloys.
Some manufacturers see that gold-plated PCBs can also be made in this way, and the price is cheap and the time is shortened, so some people sell such flash gold PCBs.
Because flash gold lacks the subsequent electroplating process, its cost is much cheaper than real electroplating gold, but because its gold layer is very thin, it generally cannot effectively cover all the nickel layer under the gold layer, so it is also relatively expensive. It is easy to cause the problem of oxidation after the circuit board is stored for a long time, which in turn affects the solderability.
Important reminder: choose the surface treatment method reasonably according to your product characteristics. If your product is an industrial grade product, if you want to guarantee the quality of your product, you must not use flash gold to save money!
