Wiring board

A wiring board, comprising:

• a glass core member having:
• a first major surface;
• a second major surface opposite the first major surface;
• and
• through holes penetrating the glass core member between the first major surface and the second major surface, each of the through holes having a first end adjacent the first major surface, a second end adjacent the second major surface, and a bottom portion at the second end;
• a first adhesion layer in close contact with the first major surface and respective inner walls of the through holes, the first adhesion layer having portions each closing the bottom portion of a respective one of the through holes;
• a second adhesion layer in close contact with the second major surface and the portions of the first adhesion layer;
• a first wiring layer disposed on the first adhesion layer;
• and
• a second wiring layer disposed on the second adhesion layer, wherein
• a proportion of remaining copper on the first major surface is set to 70 to 100%, a proportion of remaining copper of the second major surface is within 10% of the proportion of remaining copper on the first major surface, the first adhesion layer is comprised of at least one material having a first predetermined Young's modulus, and the first wiring layer is comprised of at least one material having a second predetermined Young's modulus, the first predetermined Young's modulus being 0.1 to 0.85 times the second predetermined Young's modulus,
• wherein:
• the first adhesion layer comprises a Ti film and a Cu film;
• and
• the first wiring layer comprises Cu.