The difference between gilding and sinking gold of PCB

                   The difference between gilding and sinking gold of PCB

Then the two "golden board" to circuit board can cause what influence? Let me explain for everybody, help you concept thoroughly clear.

What is gilding plated What we mean by the entire board gold-plated, gold-plated generally refers to the "electricity" "gold plating nickel plate" "electrolytic gold", "electric gold electroless nickel gold plate", distinguished by soft and hard gold (hard gold is commonly used in gold finger).Principle is to nickel and gold (commonly known as gold salt dissolves) in the chemical liquid medicine, the circuit board in electroplating cylinder and the current is switched on and in circuit board copper foil generated on the surface of nickel and gold plating, electroless nickel gold by coating high hardness, wear resistance, the advantage of not easy oxidation has been widely used in electronic products.

What are a sinking gold? Turmeric is generated by the method of chemical oxidation reduction reactions a layer of coating, the general thickness is thicker, is a kind of chemical nickel gold layer deposition method, can achieve a thick layer of gold

PCB gold plate and sinking gold difference1. Generally, the thickness of sunken gold is much thicker than that of gold-plated. The sunken gold will be golden yellow and more yellow than gold-plated. The two form different crystal structures.2. Due to the different crystal structure formed by sunken gold and sinking gold, sunken gold is easier to weld than sinking gold, which will not cause poor welding and cause customer complaints. At the same time because of the soft gold than sinking gold, so gold finger plate generally choose gold, hard gold wear.3. There is only nickel gold on the pad of the gold-plated plate, and the signal transmission in the skin effect is in the copper layer, which will not affect the signal.4. The crystal structure of sunk gold is more compact than that of gold-plated gold, and it is not easy to produce oxidation.

4, heavy metal crystal structure more compact than a gold-plated, not easy to oxidation5, as the wiring is more and more close, has reached a 3-4 mil line width and spacing, gold-plated is easy to produce gold silk short circuit. Heavy gold plate only nickel gold bonding pad, so will not produce into gold short circuit6, heavy metal plate only nickel gold bonding pad, so on a line of resistance welding and copper layer combined with stronger. Engineering did not compensate on impact on spacing.7, generally used for relative to demand higher board, flatness is better, generally with a heavy gold, zedoary generally won't appear black pad phenomenon after assembly. Heavy gold plate of smoothness and inactive life just as good as gold plated board.This is heavy gold board and the difference of gold plated board, now on the market price is expensive, in order to save the cost of gold plated board, many producers have been reluctant to production do welding plate are nickel and gold plate of gold, and the price is cheap.

Heavy gold plate with gold plate:1, the heavy gold plate with gold plate is the same kind of technology products, electric gold plate with gold plate is the same kind of technology products, in fact just different term for different populations in PCB industry, heavy gold plate with electric gold board found in the mainland, and the gold plate with the flash gold plate in Taiwan.2, heavy gold plate/gold plate is generally a formal name for the chemical nickel gold plate or nickel leaching gold plate, and the growth of nickel/gold layer is with the method of chemical deposition on the plating; The lightning gold plate/gold plate is generally formal term gold plating nickel plate or flash gold plated board, the growth of nickel/gold layer is with the method of direct current plating on the plating.

Why don't generally "tin"?As the IC integration is higher and higher, IC feet more close. And hard to turn into a tin injection for vertical thin solder leveling, this brought difficulty to SMT SMT; Another tin plate for life (shelf life) is short. The gold-plated look good solve these problems:

1, for SMT process, especially for 0603 and 0402 subminiature table, because the welding plate flatness is directly related to the quality of the solder paste printing process, play a decisive influence on the back of the reflow welding quality, so, the entire board gold-plated in high density and subminiature process often seen in the table. 2 in the development phase, the influence of factors such as components procurement is often not the board to the welding immediately, but often have to wait a few weeks or even months before use, inactive life of gold plated board (shelf life) is longer than lead tin alloy many times so everyone is willing to adopt and gold-plated PCB in degrees of the cost of the sample stage compared with pewter plates.

However, as the wiring is more and more close, has reached a 3-4 mil line width and spacing, therefore has brought the gold silk short circuit problem