Tin spray recruitment 20 17

As the name implies, tin melting is to deposit a layer of tin on the PCB pad by chemical method, with a very thin thickness, generally 10~30 microns. The main purpose is to prevent oxidation and better melt SMT tin, which is actually the same as melting gold and OSP. Tin needs to be applied in SMT process.

Tin spraying means spraying a layer of tin by physical means, the thickness is generally 50~ 150 micron, which is relatively thick. Don't tin when smt, just melt the solder paste.

These two kinds of tin must have different compositions. Tin is melted together with a salt of tin and prepared with an acidic solution containing tin. However, tin alloy is generally used for tin spraying, which is generally divided into lead and lead-free (pure tin will never be used and has a high melting point)