The main factor directly determining the quality and positioning of a board is the surface treatment process. Such as osp spray tin, gold, gold. Relative to sink gold is the face of high-end board. As a result of the quality of shen jin, relative to the cost is also relatively high. So many customers use the most commonly used spray tin process. Tin spray is divided into lead spray tin (that is, hot wind flat) and lead – free spray tin. Now you can look at the differences between the processes;

After a long time of making the circuit board, there will always be various problems, such as some end users require to make lead-free samples, and when they receive the manual welding process debugging, they always feel that there is no lead on the tin easily. At this time, I am not sure whether it is the reason of the circuit board factory or the welding itself.

In fact, when welding the sample by hand, the lead is easier to tin. Lead is much better than lead-free in that it increases the activity of the wire during welding. But lead is toxic, and lead-free tin has a high melting point and relatively strong weld points.

The presence of lead and the presence of lead can also be distinguished visually: the presence of lead tin is lighter, the absence of lead tin (SAC) is darker.

Lead-free process: a basic concept of lead-free electronic assembly is that in the soft soldering process, whether manual soldering, dip soldering, wave soldering or reflow soldering, the solder used is lead-free solder (pb-feer soder). Lead-free solder does not mean that the solder is 100% lead-free. In leaded solders, lead is present as a basic element. In lead-free solder, the base element does not contain lead.

(lead-free with lead: top to bottom)

Lead process: in the traditional soft soldering process of printed plate assembly, sn-pb solder is generally used, in which lead exists and functions as a basic element of solder alloy. Lead solder alloy melting point is low, low welding temperature, less heat damage to electronic products; Lead solder alloy wetting Angle is small, weldability is good, product solder spot “fake welding” possibility is small; The solder alloy has good toughness and the formed solder joint has better vibration resistance than lead-free solder joint.

Compared to. Osp lead-free tin-spraying and gold-sinking processes, these three surface treatments are relatively environmentally friendly.

But most regular boards are used more for both. Because the cost is lower. (picture shows osp process)

Osp is suitable for thin lines, thin SMT spacing. Low operating temperature, no damage to the plate, easy to rework and repair.

But the osp process made by the board is not acid, high humidity environment will make the welding performance affected. Need to welding in the shortest possible time to complete the heavy gold with gold plated although are more resistant to wear and tear. But with the distinguishing words: gilded craft gold plating on the surface, only the side or only copper and nickel, after a long time easy oxidation, this is a defect in the plating process, not to be used in the case of high demand.

(gold-plated and gold-plated: top to bottom)

The word that makes sink gold whole weld pad, include flank can be plated on nickel gold, it is the most stable at present, can be used in all sorts of occasions, but sink nickel gold has a more headache, also more difficult to find the problem, it is not as adhesion as gold plating, easy to fall off after using for a period of time.