Flux

Abstract

Provided is a flux that allows soldering to be performed without requiring a step of removing a Cu-OSP film even with a Cu-OSP processed substrate. This flux containing rosin, an organic acid, a benzimidazole-based compound, and a solvent is characterized in that 30% by mass or more and 70% by mass or less of the rosin, 1% by mass or more and 10% by mass or less of the organic acid, 0.2% by mass or more and 10% by mass or less of the benzimidazole-based compound, and 20% by mass or more and 60% by mass or less of the solvent, wherein the benzimidazole-based compound is composed of at least one of 2-alkylbenzimidazole and a salt of 2-alkylbenzimidazole hydrohalide.

1 . A flux containing rosin, an organic acid, a benzimidazole-based compound, and a solvent, the flux comprising:
 30% by mass or more and 70% by mass or less of the rosin;   1% by mass or more and 10% by mass or less of the organic acid;   0.2% by mass or more and 10% by mass or less of the benzimidazole-based compound; and   20% by mass or more and 60% by mass or less of the solvent,   wherein the benzimidazole-based compound includes at least one species selected from a group consisting of 2-alkylbenzimidazole and a salt of 2-alkylberizimidazole hydrohalide, and   wherein when containing an imidazole-based compound, more than 0%, by mass and 5% by mass or less of the imidazole-based compound is contained and an addition of the imidazole-based compound is equal to or less than the addition of the benzimidazole-based compound.   
     
     
         2 . The flux according to  claim 1 , wherein the flux further contains 5% by mass or less of a salt of amine hydrohalide excluding the salt of 2-alkylbenzimidazole hydrohalide, which is a total amount of the imidazole-based compound and the salt of hydrohalogenic acid when containing the imidazole-based compound and the salt of hydrohalogenic acid. 
     
     
         3 . (canceled) 
     
     
         4 . The flux according to  claim 1 , wherein the flux further contains more than 0% by mass and 10% by mass or less of a thixotropic agent. 
     
     
         5 . (canceled) 
     
     
         6 . The flux according to  claim 2 , wherein the flux further contains more than 0% by mass and 10% by mass or less of a thixotropic agent. 
     
     
         7 . (canceled)