Flux resin composition, electronic component, method for manufacturing the electronic component, mounting structure, and method for manufacturing the mounting structure

A flux resin composition comprising an epoxy resin (A), an imidazole compound (B), a thixo agent (C), and an activator (D),

• the epoxy resin (A) including at least one resin selected from the group consisting of naphthalene epoxy resins, biphenyl aralkyl epoxy resins, trisphenol methane epoxy resins, biphenyl epoxy resins, and dicyclopentadiene epoxy resins, content of the at least one resin being equal to or greater than 20% by weight with respect to a total weight of the epoxy resin (A), wherein
• with respect to a total of the epoxy resin (A), the imidazole compound (B), the thixo agent (C), and the activator (D):
• a proportion of the epoxy resin (A) is equal to or greater than 70% by weight and equal to or less than 94.7% by weight,
• a proportion of the imidazole compound (B) is equal to or greater than 0.05% by weight and equal to or less than 2.4% by weight,
• a proportion of the thixo agent (C) is equal to or greater than 0.75% by weight and equal to or less than 5.55% by weight, and
• a proportion of the activator (D) is equal to or greater than 4.25% by weight and equal to or less than 23% by weight,
• a time it takes for a value calculated by
• (viscosity of the flux resin composition after storage/viscosity of the flux resin composition at beginning of the storage)×100(%)
• to reach 120% since the flux resin composition has started to be stored at 25° C. being equal to or longer than 24 hours,
• the flux resin composition allowing a solder ball to have a wet spreadability equal to or greater than 50% before and after a reflow process, and
• a cured product of the flux resin composition having a glass transition temperature equal to or higher than 85° C.