Kynning á blý-tin ál rafhúðun í PCB iðnaði prentuðu hringrás ferli!

In the process of printing circuit boards, the surface of the steel strip usually has a plating printing process for lubrication, bonding and soldering. This process is known in the industry as electroplating lead-tin alloys. This paper briefly introduces the function and mechanism of dielectric electroplating of lead-tin alloys.

Frumefnistákn tins er Sn, atómþyngdin er 118,7, eðlismassi 7,29g/cm3 og rafefnafræðilegt jafngildi Sn2 er 2,214g/Ah. Táknið fyrir blý frumefni er Pb, atómþyngd er 207, eðlismassi er 11,4g/cm3 og rafefnafræðilegt jafngildi Pb2 er 3.865g/Ah.

Tin-lead alloy plating is a protective layer for alkali etching in the production of printed circuit boards. In this case, the lead content in the coating is not critical. When hot melt is required after etching, a 60-63% tin-lead plating must be provided. The coating should be uniform, fine, semi-bright, 8 microns thick. The coating does not require full brightness, depending on the application of the coating. In an acidic solution, lead and tin electrodes have similar potentials and are easy to co-deposit. In order to obtain different ratios of lead-tin alloy coatings, lead and tin ion concentrations and cathode current density can be controlled. Fluoroborate baths are widely used in industry.

The tin-lead alloy plating solution should have good dispersibility and deep plating ability, stable process and easy maintenance. There are many kinds of electroplating solutions, but the main ones are fluoroborate type and non-fluoroalkyl sulfonate type. The fluoride bath is stable, easy to maintain and low cost, and has become the most widely used process in PCB production for many years. However, in recent years, more and more attention has been paid to the pollution of fluoride, and the amount of fluorine-free electroplating solution is also increasing rapidly. Alkyl sulfonic acid tin-lead alloy plating solution has become more and more mature in recent years, and the prices of materials and additives have also become reasonable, and the dosage has increased year by year. At the same time, additives are no longer a single imported product, and the quality and quantity of domestic additives have been significantly improved.