First, Surface Treatment of PCB Board
Anti-oxidation, tin spraying, lead-free tin spraying, gold precipitation, tin precipitation, silver precipitation, hard gold plating
, full plate gold plating, gold finger, nickel palladium gold OSP: lower cost, good solderability, harsh storage conditions, short time, environmental protection technology, good soldering, smooth. Tin spraying: Tin spraying board is a multi-layer (4-46 layers) high precision PCB template, which has been used by many large domestic communication, computer, medical equipment and aerospace enterprises and research units in the connecting part between memory strip and memory slot. All signals are transmitting through the golden hand.
The golden finger is actually coated with gold through a special process on the copper clad laminate, because gold has strong antioxidant activity and conductivity. However, because of the high price of gold, more memory is now replaced by tin plating. Tin materials have been widely used since the 1990s. At present, the "golden finger" of motherboard, memory and graphics cards are almost all in the tin materials. Only parts of high-performance servers/workstations will continue to use the gold plating method, which is naturally expensive.
Second, Why do they need Gold Plating
With the increasing integration of IC, the IC feet became more and denser. Vertical tin spraying process is difficult to smooth the thin solder pad, which brings difficulties to SMT mounting. In addition, the shelf life of tin spraying board is very short. And the gold-plated PCB plate just solved these problems:
1. For surface mounting technology, especially for 0603 and 0402 super-miniature surface mounting, the pad smoothness is directly related to the quality of solder paste printing process, and plays a decisive role in the quality of reflow welding, so gold plated pcb board
is common seen in high density and super-miniature surface mounting technology.
2. In the trial-manufacture stage, the influence of component purchasing and other factors is not that the plate will be welded immediately, but that it will often wait several weeks or even a month to use. The shelf life of the gold plated pcb board is many times longer than that of the lead-tin alloy, so everyone is willing to use it.