An interconnection substrate includes: an interconnection layer region
where at least a first conductor layer and a second conductor layer are
vertically stacked in that order on a substrate, with the first conductor
layer and second conductor layer containing conductive particles and a
binder, wherein the first conductor layer and second conductor layer
stacked in the interconnection layer region have conductive particles
different in average particle size from each other. As a result, only an
intended region can have low resistance.