Circuit board immersion gold board and circuit board gold-plated board are commonly used processes in the production of circuit boards today.
With the higher and higher integration of IC, the more and denser IC pins are. The vertical tin spray process is difficult to blow the thin pads flat, which brings difficulties to the SMT placement; in addition, the standby life of the tin spray board is very short. The gold-plated circuit board just solves these problems. For the surface mount process, especially for the ultra-small surface mount, because the flatness of the pad is directly related to the quality of the solder paste printing process, it has a decisive impact on the quality of the subsequent reflow soldering. It is often seen in the ultra-small surface mount process. In the trial production stage, affected by factors such as component procurement, it is often not the board that will be soldered immediately, but often it will take several weeks or even a month to use it. The standby life of the gold-plated board is many times longer than that of the tin board. . So everyone is willing to use it. Besides, the cost of the gold-plated sample stage is almost the same as that of the lead-tin alloy plate.
what is gold plating
Gold plating refers to electroplated gold, electroplated nickel-gold plate, electrolytic gold, electro-gold, electro-nickel-gold plate, and has the distinction of soft gold and hard gold (generally used as gold fingers). The principle is to dissolve nickel and gold (commonly known as gold salt) in chemical water, immerse the circuit board in an electroplating tank and apply current to form a nickel-gold coating on the copper foil surface of the circuit board. The characteristics of high hardness, wear resistance, and non-oxidation are widely used in electronic product names.
What is Immersion Gold
Immersion gold is a layer of coating formed by chemical redox reaction. Generally, the thickness is thicker. It is a kind of deposition method of chemical nickel-gold layer.
The difference between immersion gold plate and gold-plated plate
First, the crystal structure formed by immersion gold on the circuit board is different from that formed by gold plating on the circuit board. The thickness of immersion gold is much thicker than that of gold plating, and the immersion gold will be more golden yellow than gold plating, and customers are more satisfied.
Second, immersion gold is easier to weld than gold plating, and it will not cause poor welding and cause customer complaints. The stress of the immersion gold plate is easier to control, and for products with bonding, it is more conducive to the processing of bonding. At the same time, it is precisely because immersion gold is softer than gold plating, so the gold finger of immersion gold plate is not wear-resistant.
Third, the immersion gold board only has nickel gold on the pad, and the transmission of the signal in the skin effect is in the copper layer and will not affect the signal.
Fourth, the crystal structure of immersion gold is denser than that of gold plating, and it is not easy to produce oxidation. Make process choices according to your product needs.
Fifth, as the wiring becomes denser, the line width and spacing have reached 3-4MIL. Gold plating is prone to short circuit of gold wires. The immersion gold board only has nickel gold on the pad, so there will be no gold wire short circuit.
Sixth, the immersion gold plate of the circuit board only has nickel gold on the pad, so the combination of the solder mask on the circuit and the copper layer is stronger. The project will not affect the spacing when compensating.
Seven, it is generally used for boards with relatively high requirements, and the flatness is better. Generally, the circuit board is immersed in gold, and the immersion gold generally does not appear black pad phenomenon after assembly. The flatness and standby life of the immersion gold plate are as good as those of the gold-plated plate.
Post time: Sep-28-2022