PURPOSE: To obtain the cream solder having excellent solderability and low corrosiveness by incorporating isopropylamine hydrobromide as the activator in a flux into the cream solder formed by kneading a flux and solder powder.

CONSTITUTION: The effect of an activator is exhibited and the low corrosive cream solder is obtd. without requiring the addition of an activator of an amine hydrochloride system if the IPA-HBr is compounded with the cream solder. This cream solder contains 87 to 93% powder solder, 1 to 6% resin, 1 to 8% solvent, 0.1 to 1.0 thixo agent, and 0.01 to 0.2% isopropylamine hydrobromide. Rosins, for example, polymerized rosins, natural rosins, etc., are used as the resin. An org. solvent is usable as the solvent. Hardened castor oil, coconut oil, etc., are used as the thixo agent. The need for washing after soldering is eliminated by adding the IPA-HBr to the activator. The workability and productivity in a packaging line are greatly improved in this way.