| 摘要 |
<p>PROBLEM TO BE SOLVED: To overcome the problem of a prior art such that a circuit conductor layer is difficult to be finer because of irregularities on the multilayer interconnection substrate surface comprising an organic resin insulating layer containing a fiber base material while a poor connection between an electronic part and a circuit conductor layer as well as a degradation in insulation between the circuit conductor layers occur. SOLUTION: A multilayer interconnection substrate 5 is provided which comprises an insulating substrate 2 comprising a plurality of insulating layers 1 where the fiber base material is impregnated with an organic resin, and a circuit conductor 4 provided both on surface and inside the insulating substrate 2, with an electronic part mounted on at least one surface. A surface coat layer 3 is formed on the surface, where an electronic part is mounted, which comprises an organic insulating resin comprising an inorganic insulating filler, with a saturation water-absorption coefficient 0.2% or less and a surface roughness Rmax being 5μm or less. The circuit conductor layer 4 on the surface of the multilayer interconnection substrate 5 is micronized while an insulation reliability between the circuit conductor layers 4a is improved.</p> |
