Multilayer circuit board with resin bases and separators

A multilayer circuit board comprising:

• a plurality of resin bases stacked while respectively placing a separator in between;
• a plurality of interconnect patterns formed on one surface of each of said plurality of resin bases, each of the plurality of interconnect patterns having a curved shape with a first pattern of the plurality of interconnect patterns being formed on a first one of the resin bases and a second pattern of the plurality of interconnect patterns being formed on a second one of the resin bases, the first pattern having a first connecting end and a second connecting end, the second pattern having a third connecting end and a fourth connecting end;
• and
• electro-conductive bumps which are formed to extend through said resin bases and said separators, so as to electrically connect said plurality of interconnect patterns such that a first electro-conductive bump electrically connects the second connecting end to the third connecting end, with the fourth connecting end overlaying the first connecting end but being spaced apart from the first connecting end by the separator in between, the first pattern and the second pattern forming a helix as a whole through the first electro-conductive bump, said resin bases and said separators being heat-bonded,
• said separators being composed of a first thermoplastic resin material having a first glass transition temperature, and
• each of said resin bases being composed of a second thermoplastic resin material having a second glass transition temperature higher than said first glass transition temperature.