ENIG PCB and flash gold PCB are commonly used in PCB design and PCB production. With the increasing integration of IC, IC pins are more and more dense. However, it is difficult for HASL process to blow even the fine pad, which brings difficulty to SMT assembly; in addition, HASL PCB has a short service life. Flash gold PCB solves these problems. Because the pad flatness is directly related to the quality of solder paste printing process, and has a decisive impact on the subsequent reflow welding quality, the whole board flash gold is often seen in high-density and ultra-small surface mounting process. In the trial production stage, affected by factors such as component procurement, it is not often that the boards are soldered immediately when they come, but that it often takes weeks or even months to use them. The standby life of flash gold PCB is many times longer than that of HASL PCB. In addition, the cost of flash gold PCB design in the sample stage is almost the same as that of lead tin alloy plate.
ENIG is a kind of electroless nickel gold deposition method, which can achieve a thicker gold.
The principle of flash gold is that nickel and gold (commonly known as gold salt) are dissolved in the chemical solution, the circuit board is immersed in the electroplating cylinder and connected with the current to generate nickel gold coating on the copper foil surface of PCB. Because of its high hardness, wear resistance and non oxidation characteristics, electroplated gold is widely used in electronic products.