Explanation of PCB Immersion Gold Process
1.What is Immersion Gold?
Simply put, Immersion Gold is a method of chemical deposition that produces a metal coating on the surface of the circuit board through a chemical oxidation-reduction reaction.
2.Why do we need Immersion Gold?
The copper on the circuit board is mainly red copper. The copper solder joints are easily oxidized in the air, which will cause poor conductivity, that is, poor tinning or poor contact, reducing the performance of the circuit board.
Then it is necessary to perform surface treatment on the copper solder joints. Immersion Gold is to plate gold on them. Gold can effectively block copper metal and air to prevent oxidation. Therefore, Immersion Gold is a surface anti-oxidation treatment method. It is a layer of gold on the surface of copper through a chemical reaction, also called chemical gold.
3.What are the benefits of surface treatment such as Immersion Gold?
The advantage of the Immersion Gold process is that the color of the deposit on the surface is very stable when the circuit is printed, the brightness is very good, the coating is very flat, and the solderability is very good.
The thickness of the gold in the Immersion Gold is generally 1-3Uinch, so the gold thickness produced by the surface treatment method of Immersion Gold is generally thicker.
The surface treatment method of immersion gold is currently widely used in circuit boards such as keypads and gold finger boards, because gold has strong conductivity, good oxidation resistance and long service life.
4.What are the advantages of using immersion gold circuit boards?
Immersion gold boards are bright in color, good in color and good in appearance.
The crystal structure formed by immersion gold is easier to weld than other surface treatments, and can have better performance and ensure quality.
Because the immersion gold board only has nickel gold on the pad, it will not affect the signal, because the signal transmission in the skin effect is in the copper layer.
The metal properties of gold are relatively stable, the crystal structure is denser, and it is not easy to oxidize.
Because the immersion gold board only has nickel gold on the pad, the combination of the solder mask on the circuit and the copper layer is more solid, and it is not easy to cause micro short circuits.
The project will not affect the spacing when making compensation.
The stress of the immersion gold board is easier to control.
5.Immersion gold and gold fingers
To put it bluntly, the gold finger is a brass contact, which can also be said to be a conductor.
In detail, because gold has strong anti-oxidation and strong conductivity, the parts connected to the memory slot on the memory stick are plated with gold, so all signals are transmitted through the gold fingers.
Because the gold fingers are composed of many yellow conductive contacts, their surface is plated with gold and the conductive contacts are arranged like fingers, hence the name.
In layman’s terms, the gold fingers are the connecting parts between the memory stick and the memory slot, and all signals are transmitted through the gold fingers.
The gold fingers are composed of many golden conductive contacts. The gold fingers are actually a layer of gold on the copper clad board through a special process.
Therefore, the simple distinction is that immersion gold is a surface treatment process for circuit boards, and the gold fingers are components on circuit boards with signal connection and conduction.
In the actual market, the gold fingers may not be truly gold on the surface. Because of the high price of gold, more memory is currently replaced by tin plating.
Tin materials have become popular since the 1990s. Currently, the “gold fingers” of motherboards, memory cards, graphics cards and other devices are almost all made of tin materials. Only the contact points of some high-performance server/workstation accessories continue to use gold plating, which is naturally very expensive.