We know that whether a PCB circuit board is proofing or manufacturing, a lot of information is needed during the period, such as size, board thickness, surface treatment, resistance value, solder mask coverage, solder mask color, gold finger, copper foil thickness, and so on. In the entire PCB link, the different parameters of each link will affect the final price. Under the same overall cost conditions, the largest proportion is the surface treatment, such as immersion gold and gold plating.

So the question is, why should I use immersion gold and gold plating? In fact, this is related to the current new technology. Nowadays, there are more and more pins of BGA/IC, and the integration level is very high. However, the current vertical tin spraying process is difficult to flatten the small pads. If there are problems in the early stages of production, the subsequent production problems will be more or even difficult to solve. Especially the difficulty of SMT placement will increase exponentially. In addition, the life cycle of the tin spray board is very short, so the time spent on manufacturing will be doubled.

However, because of the metal coating on the surface of the immersion gold and gold-plated boards, the service life cycle is relatively long compared with the tin-sprayed boards. Under normal circumstances, a PCB board will not be produced immediately for the next step, because the procurement of components also takes time, usually a few weeks or even a month or so, so the storage conditions of the PCB must be strict.

For the SMT chip placement process, especially the small surface mount process, because the flatness of the pad is directly related to the quality of the solder paste printing process and the quality of the reflow soldering, the SMT and DIP plug-in post-soldering If quality problems occur, subsequent product batches will be poor. Therefore, the best solution is to use metal plating to solve it, that is, immersion gold, gold plating. The most important thing is that the quality of immersion gold, gold-plated board and tin-gold board is more stable except that the overall cost is not much different. This can reduce a lot of unnecessary troubles for PCB manufacturers, so why not do it?