What is the role of gold and gold fingers in the PCB circuit board

First of all, let’s introduce what is Shen Jin? The copper on the circuit board is mainly red copper, and the copper solder joints are easily oxidized in the air, which will cause conductivity, that is, poor tin eating or poor contact, and reduce 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 treatment method for surface oxidation prevention. It is a chemical reaction to cover the surface of copper with a layer of gold, also known as Chemical gold.

First of all, let’s introduce what is Shen Jin? The copper on the circuit board is mainly red copper, and the copper solder joints are easily oxidized in the air, which will cause conductivity, that is, poor tin eating or poor contact, and reduce 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 treatment method for surface oxidation prevention. It is a chemical reaction to cover the surface of copper with a layer of gold, also known as Chemical gold.

What is the role of gold and gold fingers in the PCB circuit board

So what is a gold finger? Let’s say it more bluntly, that is, brass contacts, or conductors. In detail, it is the component connected to the memory slot on the memory module. All signals are transmitted through golden fingers. It consists of numerous yellow conductive contacts. The surface is gold-plated and the conductive contacts are arranged like fingers. name.

The advantage of the immersion gold process is 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. Generally, the thickness of immersion gold is 1-3 Uinch, which can be basically divided into four stages to complete: pre-treatment (degreasing, micro-etching, activation, post-dipping), immersion nickel, immersion gold, post-treatment (waste gold washing, DI water washing) ,drying).

However, in terms of production costs, the immersion gold process is more expensive than other spray tin processes. If the thickness of the gold exceeds the conventional process of the plate making plant, the cost will be more expensive. Of course, if you are concerned about the weldability and electrical properties of the board It is a different matter if there are higher requirements. For example, if your circuit board has gold fingers and needs to be gold-immersed, or the line width/pad spacing of the board is insufficient, then it is best to do the process of gold-immersion + gold-plated fingers, so that the circuit board soldering is very good , The performance of the circuit board is also very stable, the pad will not fall off, the contact will not be bad, and there will be no short circuit, etc., and it is also very shock-proof and drop-proof. Of course, we will not drop the board.

Another situation is that the circuit board has gold fingers, but the surface of the board other than the gold fingers can be sprayed with tin according to the situation, that is, the process of spraying tin + gold-plated fingers, the circuit board has sufficient line width and pad spacing, and the soldering requirements are not In the case of high, the production cost can be effectively reduced without affecting the use of the board. However, if the line width of the board and the pad spacing are insufficient, the use of tin spraying technology in this case will increase the difficulty of production. There will be more short circuits such as tin bridging, and the golden fingers will often be inserted and stripped. The phenomenon of poor contact.

Therefore, we can choose the appropriate board-making process according to the actual situation of our circuit board, that is, the cost is controlled without affecting the use of the board.

The Links:   SP14Q003-A NL160120BC27-19

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