What is the purpose of gold immersion on the surface of printed circuit boards?
The means of gold immersion process is being PCB board printed route nominal stacking colour stability, good finish, flat plating, excellent solderability nickel-gold plating.Easy to say, sinking gold is the adoption of chemical stacking method, through the chemical oxidation recovery reaction in the route board nominal layer of non-metallic plating.
First, the role of immersion gold process
The copper on the access board is mainly red copper, copper soldering joints in the atmosphere is simple to be oxidised, that will form the heterogeneity is to eat tin is not good or contact is not good, elevated the function of the access board, then the need for copper soldering joints to stop the nominal solution, immersion gold is below the study, the gold can be an effective barrier to the copper non-metallic and amicable atmosphere to prevent oxidation, because the immersion gold is the nominal oxidation prevention of a form of solution, it is Through the chemical reaction in the name of copper covered with a layer of gold, also known as chemical gold.
Immersion gold process benefits are being printed on the route when the nominal pile of colour is very stable, good finish, plating layer is very flat, weldability is very good. Sinking gold normal gold thickness of 1-3 Uinch, because sinking gold this nominal solution form to do into the gold thickness of the normal thicker, because sinking gold this nominal solution form widely used in keypad, gold finger boards and other route boards, due to the strong heterogeneity of the gold, oxidation resistance is good, the use of long life.
Third, the adoption of immersion gold plate route board benefits
1, immersion gold plate colour delicate, good colour, ugly, promote the degree of absorption for the depositors.
2, Immersion gold composed of crystalline structure than the rest of the nominal solution easier riveted, can occupy a better function, quality assurance.
3, because of the sunken gold plate is only on the pad nickel gold, will not have a reaction to the signal, because the skin effect in the transmission of the signal is in the copper layer.
4, the non-metallic properties of gold is relatively stable, the crystalline structure is more compact, not easy to have oxidation reactions.
5, because of the immersion gold plate as long as the pads on the nickel gold, because the route of the solder resist and the copper layer of the joint more solid, but also not simple to form a micro-short circuit.
6, the work is being made up for the distance will not react, convenient task.
7, the stress of immersion gold plate is easier to grasp, the experience is better when using.
Fourth, the difference between immersion gold and gold fingers
Gold fingers we say more straightforward, is the brass contacts, can also be said to be a superconductor. Detailed that is because of the gold oxidation resistance is very strong, and the spread is also very strong, because the external memory strip and the external memory slot connected to the components plated with gold, so that all the signals are passed through the gold finger to pass. Because the gold finger consists of a flood of yellow heat-conducting contact sheets, its name is studied and the heat-conducting contact sheets are displayed like a finger, so it is named. In general, the gold finger is the connection element between the external memory strip and the external memory slot, and all the signals are transmitted through the gold finger. Gold finger by the flood of gold-coloured thermal conductive contact sheet composition, gold finger in practice is in the copper-clad board through a special process and then coated with a layer of gold.
Because, it is easy to distinguish that the immersion gold is a kind of nominal solution process of the route board, and the golden finger is the element that occupies the signal connection and conduction on the route board. In the market practice, the gold finger must be really nominal for gold. Because of the high price of gold, more memory are adopted in front of the tin plating to replace, from the last century 90 era started tin material began to improve, in front of the motherboard, memory and graphics card and other facilities of the "gold finger" are adopted tin material, as long as the whole of the high-functioning server / task station accessories contact point will continue to adopt the practice of studying abroad! The price is certainly not expensive.
