Gold plated board and gold-plated board are commonly used in circuit board production. With the increasing integration of IC, IC pins are more and more dense. In addition, the shelf life of the solder plate is very short. And the gold plate just solves these problems.
For surface mount process, especially for 0603 and 0402 ultra small surface mount, because pad flatness is directly related to the quality of solder paste printing process, and has a decisive impact on the subsequent reflow soldering quality, so the whole board gold plating is often seen in high-density and ultra small surface mount process. In the trial production stage, affected by factors such as component procurement, it is often not that the board is welded immediately when it comes, but that it often takes several weeks or even months to use. The shelf life of gold-plated plate is many times longer than that of tin plate. So everyone is happy to use it. In addition, the cost of gold-plated PCB in the sample stage is almost the same as that of lead tin alloy plate.
1、 What is gilding: gilding the whole board. It generally refers to [electroplated gold], [electroplated nickel plated gold plate], [electrolytic gold], [electroplated gold] and [electroplated nickel plated gold plate], which can be divided into soft gold and hard gold (generally used as gold finger). Its principle is to dissolve nickel and gold (commonly known as gold salt) in the chemical solution, immerse the circuit board in the electroplating tank and apply the current to form a nickel gold coating on the copper foil surface of the circuit board. The nickel gold coating is widely used in electronic products because of its high hardness, wear resistance and non oxidation.
What is gold deposition: through chemical oxidation-reduction reaction to produce a layer of coating, generally thick, is a kind of chemical nickel gold layer deposition method, can achieve a thicker gold layer, usually called gold deposition.
Difference between gold plate and gold plate
1. The crystal structure formed by gold deposition is different from that formed by gold plating. The thickness of gold deposition is much thicker than that of gold plating. The gold deposition will be golden yellow, which is more yellow than that of gold plating, and the customer is more satisfied.
2. The crystal structure formed by gold deposition is different from that formed by gold plating. Gold deposition is easier to weld than gold plating, which will not cause bad welding and cause customer complaints. The stress of the gold plate is easier to control, and it is more conducive to bonding processing for bonded products. At the same time, it is also because the gold plate is softer than the gold plate, so the gold finger made of the gold plate is not wear-resistant.
3. There is only nickel gold on the pad of the gold plate, and the signal transmission in the skin effect is in the copper layer, which will not affect the signal.
4. Compared with gold plating, the precipitated gold has a denser crystal structure and is not easy to be oxidized.
5. With more and more dense wiring, the line width and spacing have reached 3-4mil. Gold plating is easy to produce gold wire short circuit. There is only nickel gold on the pad of the sinking gold plate, so there is no gold wire short circuit.
6. There is only nickel gold on the pad of the sinking gold plate, so the resistance welding on the circuit is more firmly combined with the copper layer. The distance will not be affected when the project is compensated.
7. Generally used for relatively high requirements of the board, the flatness is better, generally use the sinking gold, sinking gold generally will not appear after the assembly of the black pad phenomenon. The flatness and standby life of the gold plate are as good as that of the gold plate.