| 摘要 |
PROBLEM TO BE SOLVED: To provide a solder bonding reinforcing agent composition with which high bonding strength can be obtained and which can prevent solderability from decreasing without increasing the number of steps after an electronic component is mounted, and to provide a method of manufacturing a mounting substrate using the same. SOLUTION: The solder bonding reinforcing agent composition (5) is characterized in that when viscosity of the solder bonding reinforcing agent composition (5) is measured by a viscosity measuring device every 5 to 7 seconds from right after an atmospheric temperature of the solder bonding reinforcing agent composition begins to be raised when the atmospheric temperature is raised at a temperature raising speed of 0.1 to 0.2°C/second from 40°C being a temperature raising start temperature to the solder melting point of lead-free solder powder and then held for 10 minutes at the solder melting point, viscosity V<SB>1</SB>(Pa s) right after the start of temperature raising, lowest viscosity V<SB>2</SB>(Pa s) during the temperature raising from right after the start of temperature raising to the melting point, and viscosity V3 (Pa s) right after the holding at the solder melting point for 10 minutes after the temperature raising satisfy V<SB>2</SB><V<SB>1</SB>/10 and V<SB>3</SB>>10V<SB>2</SB>. COPYRIGHT: (C)2011,JPO&INPIT |
