Effects of Various Metallic Sulfates on Dissolution of Zn into Molten Sn

Abstract

In the flux action of soldering, it was found that the reaetion teek place between a metallic sulfate and molten Sn solder, which resulted in dissolution of a metal into molten Sn from metallic sulfate. ln seldering, the disselution of a metal inte solder from the base plate became remarkable at high tempreratuxe,
The present paper was concerned with the dependence ef Zn disselution from substrate into melten Sn, on the disselution of a rneta1 resulting from the reaction between a metallic sulfate and molten Sn,
The results obtained ware as follows,
1) The disselution of Zn from substrate into Sn soider was atccelerated by a sulfate of Ag, Ce, Cu or Ni.
2) ln such cases as the above, it was confirmed that Ag-Zn, Cu Zn, Co-Zn or Ni-Zn layer of alloy was produced,
3) A sulfate of Bi or Pb had little influence on the d3ssolutien ef Zn into Sn solder.
4) lt was considered that the dissolution of Zn from the substrate into Sn solder was aceelerated in the case ef dH decrease fer the alloying between Zn and a rental whereas the Zn-dissolution was hardly influenced in the case ef dH increase.
5) ln the case of a metal-Sn allOy solder instead of pure Sn, the disselutien of Zn from the substrate into Sn solder was accelerated by an alloying metql of Ag, while such an alloying metal as Bi or Pb suppresed the dissolution of Zn into the solder, i