1. A method of manufacturing the electronic board, the method comprising:preparing a substrate in which solder parts are on electrodes of the substrate;
preparing a mounting sheet having a resin layer in which a plurality of voids coincide with positions of the electrodes;
attaching the resin layer to at least one of a first electronic component and the substrate so that interfaces of the first electronic component or the solder parts are located inside the respective voids;
causing the interfaces and the solder parts to face each other at positions of respective voids; and
melting the solder parts by heating to join the interfaces and the electrodes, wherein:
the resin layer has a shape configured to cover positions on the substrate corresponding to at least four corners of the first electronic component in a planar view,
the preparing includes preparing the mounting sheet to have at least four independent resin layers, and
the attaching includes attaching the resin layers at positions corresponding to the four corners of the first electronic component to at least one of the first electronic component and the substrate.