Patent ID: 8679263

Claim:
A solder bonding structure in which an electronic component is mounted on a main surface of a substrate including an electrode section and an insulating film, and the electrode section and the electronic component are electrically bonded to each other through a solder section, and a flux residue exuded from the solder section is present between the electronic component and the insulating film, wherein the flux contains an acrylic resin, an activating agent, and a thixotropic agent having a hydroxyl group, and the glass transition point of the acrylic resin is not higher than −62° C., or not lower than the softening temperature of the flux residue, and the flux residue has a maximum value of 300×10 −6 /K or less in linear thermal expansion coefficient within a temperature range from −40° C. to the softening temperature of the flux residue.