| abstract |
An object of the present invention is to suppress the diffusion of nickel into a molten solder alloy at the time of soldering, prevent the concentration of phosphorus from being improved, improve the bonding strength of soldering, and provide silver and / or copper to portions other than the circuit pattern. The purpose of the present invention is to suppress the reductive precipitation of. Kind Code: A1 A flux used for soldering a circuit in which electroless nickel plating or gold plating is further performed on electroless nickel plating, wherein the flux contains silver ion and / or copper ion complex. It contains one kind or two or more kinds. [Selection diagram] None |