Solder bump forming member, method for manufacturing solder bump forming member, and method for manufacturing electrode substrate provided with solder bump

A method for manufacturing an electrode substrate provided with solder bumps, the method comprising:

• a preparing step of preparing a solder bump forming member comprising a base substrate, and preparing a substrate having a plurality of electrodes arranged on a surface of the substrate,
• wherein the solder bump forming member comprises a plurality of recesses formed in a surface of the base substrate, and a plurality of solder particles in the recesses, and each of the solder particles has an average particle diameter of 1 to 35 μm and a C.V. value of 20% or less, and a part of each of the solder particles projects from the respective recess;
• a disposing step of allowing the surface of the base substrate having the recesses formed therein and the surface of the substrate having the electrodes to face each other so as to bring each electrode of the plurality of electrodes into contact with a respective solder particle of the plurality of solder particles;
• and
• a heating step of heating the respective solder particles at a temperature equal to or higher than a melting point of the solder particles,
• wherein a planar portion is formed on a part of a surface of each of the solder particles.