Reasons why the board should be gold plated

 As ICs become more integrated, the IC pins are more dense. The vertical tin-spraying process is difficult to flatten the thinned pads, which makes the placement of the SMT difficult; in addition, the standby life of the tin-coated board is very short. The gold plate just solves these problems:

1. For surface mount technology, especially for 0603 and 0402 ultra-small surface mounts, because the flatness of the pad is directly related to the quality of the solder paste printing process of the circuit board, it has a decisive influence on the quality of the reflow soldering. Whole plate gold plating is common in high density and ultra small surface mount processes.

2, in the trial production stage of the circuit board, affected by factors such as component procurement, often the board is not immediately welded, but often has to wait for a few weeks or even a month, the life of the gold-plated board is better than lead-tin The alloy is many times longer, so everyone is happy to adopt it.

    In addition, the cost of the gold-plated circuit board in the sample stage is comparable to that of the lead-tin alloy plate. But as the wiring gets denser, the line width and spacing have reached 3-4 MIL. Therefore, the problem of short circuit of gold wire is brought about: As the frequency of the signal is higher and higher, the effect of the signal transmission in the multi-plating layer on the signal quality is more obvious due to the skin effect. The skin effect refers to: high frequency alternating current, the current will tend to concentrate on the surface of the wire. According to the calculation, the skin depth is related to the frequency.