PCB News - Circuit board factory: why do PCB boards use sinking gold technology

Circuit board factory: why do PCB boards use sinking gold technology

There is a very common process used in the surface treatment of PCB boards in electronic circuit board factories, called Immersion Gold.

One, what is an immersion gold circuit board

To put it simply, immersion gold is the use of chemical deposition to produce a layer of metal coating on the surface of the circuit board through a chemical oxidation-reduction reaction.

Second, why do you want to sink gold

The copper on the circuit board is mainly red copper, and the copper solder joints are easily oxidized in the air, which will cause electrical conductivity, that is, poor tin eating or poor contact, which reduces the performance of the circuit board, so the copper solder joints need to be surface treated, Immersion gold is to plate gold on it. Gold can effectively block the copper metal and air to prevent oxidation. Therefore, Immersion gold is a surface anti-oxidation treatment. It is a chemical reaction to cover the surface of copper with a layer of gold, also called Chemical gold.

3. What are the benefits of surface treatment like immersion gold?

The advantages of the immersion gold process are that the color deposited 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. Immersion gold generally has a thickness of 1-3 Uinch, so the thickness of the gold made by the surface treatment method of Immersion Gold is generally thicker, so the surface treatment method of Immersion Gold is generally used in key boards, gold finger boards and other circuit boards., Because gold has strong conductivity, good oxidation resistance and long service life.

Four, what are the advantages of circuit boards using immersion gold circuit boards

mainly has the following points:

1. The stress of the immersion gold circuit board is easier to control.

2. The project will not affect the spacing when making compensation.

3. Immersion gold circuit boards are bright in color, good in color and attractive in appearance.

4. The metal properties of the circuit board immersion gold are relatively stable, the crystal structure is denser, and the oxidation reaction is not easy to occur.

5. The crystal structure formed by immersion gold is easier to weld than other surface treatments, and it can have better performance and ensure quality.

6. Because the immersion gold circuit board only has nickel and gold on the pad, it will not affect the signal, because the signal transmission in the skin effect is on the copper layer.

7. Because the immersion gold circuit board only has nickel and gold on the pads, the solder mask on the circuit and the copper layer are more firmly bonded, and it is not easy to cause micro short circuits.

Five, immersion gold (immersiongold) and golden finger (connectingfinger)

The gold fingers on the circuit board are more straightforward, they are brass contacts, or conductors. To be more specific, because gold is highly resistant to oxidation and conductive, the parts connected to the memory socket on the memory stick are plated with gold, and then all signals are transmitted through the gold fingers. Because the gold finger is composed of numerous yellow conductive contacts, the surface of which is gold-plated and the conductive contacts are arranged like fingers, hence the name. In layman's terms, the gold finger is the connecting part between the memory stick and the memory slot, and all signals are transmitted through the gold finger. The gold finger on the circuit board is composed of many golden yellow conductive contacts. The gold finger is actually coated with a layer of gold on the copper clad board through a special process.

Therefore, the simple distinction is that gold is a surface treatment process for circuit boards, and gold fingers are components that have signal connections and conduction on the circuit board. In the actual market, gold fingers may not really be gold on the surface. Because of the high price of gold, most memories are now replaced by tin plating. Tin materials have been popular since the 1990s. At present, the "golden fingers" of motherboards, memory and graphics cards are almost all made of tin. Materials, only part of the contact points of high-performance servers/workstations will continue to be gold-plated, which is naturally expensive.