Surface mounting method utilizing active resin composition

A surface mounting method comprising:

• applying a curable active resin composition to at least a part of a surface of a printed wiring substrate, the curable active resin composition comprising an epoxy resin in an amount of 100 parts by weight, a blocked carboxylic acid compound in an amount of 1 to 50 parts by weight and/or a carboxylic acid compound in an amount of 1 to 10 parts by weight, and a curing agent which can initiate curing reaction at 150° C. or higher, in an amount of 1 to 30 parts by weight;
• optionally, as needed, drying the applied curable active resin composition;
• optionally, as needed, heating the applied curable active resin composition at a temperature which is equal to or higher than the softening temperature of the applied curable active resin composition and which is lower than the curing reaction-initiating temperature of the applied curable active resin composition;
• subsequently, mounting a surface mount device on the printed wiring substrate by contacting the applied curable active resin composition with the surface mount device;
• performing reflow soldering on the mounted device;
• putting a curable under-filling resin into a space of interest of the reflow soldered device;
• and
• thermally curing the applied curable active resin composition and the curable under-filling resin of the reflow soldered device;
• wherein the method further comprises at least one of the following additional steps:
• (i) heating and/or performing a vacuum treatment on the applied curable active resin composition of the reflow soldered device before putting the curable under-filling resin into a space of interest of the reflow soldered device, wherein said heating is performed at a temperature lower than the curing reaction-initiating temperature of the applied curable active resin composition;
• and (ii) heating and/or performing a vacuum treatment on the applied curable active resin composition and the curable under-filling resin of the reflow soldered device after putting the curable under-filling resin into a space of interest of the reflow soldered device, wherein said heating is performed at a temperature lower than the curing reaction-initiating temperatures of the applied curable active resin composition and curable under-filling resin.