May. 16, 2019
Aluminum pcb manufacturer shares that process requirement is a very important factor in PCB production, which directly determines the quality and positioning of a board. For example, spray tin, gold, gold is relatively facing the high-end board. Due to the good quality, the cost of gold is relatively high. So many customers choose the most commonly used tin jet process. Many people know how to spray tin, but they don't know that there are two kinds of tin: leaded tin and lead-free tin. Today, PCB fabrication manufacturer China to give you a detailed description of the lead tin and unleaded tin distinction, for your reference.
1, from the surface of tin tin tin is bright, lead-free tin (SAC) is dim. Lead-free is less permeable than lead-free.
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2,The lead in lead is bad for you, but the lead without lead is not. The eutectic temperature with lead is lower than that without lead. How much depends on the composition of lead-free alloy, like SNAGCU eutectic is 217 degrees, the welding temperature is eutectic temperature plus 30~50 degrees. It depends on the actual adjustment. Lead eutectic is 183 degrees. Mechanical strength and brightness with lead are better than without lead.
3, the lead content of lead-free tin does not exceed 0.5, and the lead content reaches 37.
4, lead will improve the activity of tin wire in the welding process, lead tin wire is relatively easier to use than lead-free tin wire, but lead is toxic, long-term use is not good for the human body, and lead-free tin than lead tin melting point is high, so the welding point is much stronger.