Printed wiring board and a method of manufacturing a printed wiring board

A method for manufacturing a printed wiring board, comprising:

• forming a penetrating hole for a through-hole conductor in a core substrate formed of a single layer;
• forming a first conductive circuit on a first surface of the core substrate;
• forming a second conductive circuit on a second surface of the core substrate on an opposite side with respect to the first surface;
• forming a through-hole conductor in the penetrating hole such that the through-hole conductor connects the first conductive circuit and the second conductive circuit;
• laminating at least one first interlayer insulation layer on the first surface of the core substrate;
• and
• laminating at least one second interlayer insulation layer on the second surface of the core substrate,
• wherein the core substrate has a thickness in a range of from about 0.06 mm to about 0.40 mm and a thermal expansion coefficient α in a range of from 5×10−6 to 8×10−6, and the core substrate, the first interlayer insulation layer and the second interlayer insulation layer satisfy an equation, α/(E×(a+b+c))=0.5×10−6˜2.5×10−6/GPa·mm·K, where the thermal expansion coefficient of the core substrate is set at α, Young's modulus of the core substrate is E, a thickness of the core substrate is a, a sum of a thickness of the first interlayer insulation layer is b, and a sum of a thickness of the second interlayer insulation layer is c.