the surface of the multilayer chip in an embodiment of the present invention in the present invention the wiring layer is made of a metal for example but not limited to copper but also contains a mixture of both insulative materials and conductive materials the insulative material is a base material for example a polyimide or a low k material the conductive material is a wiring pattern made of a metal for example copper the thermal conductivity of the insulative material and the thermal conductivity of the conductive material differ by nearly two orders of magnitude in an embodiment of the present invention as illustrated in fig5 the thermal conductivity of the insulative material is 0 4 to 2 w mk and the thermal conductivity of the conductive material is 400 w mk in an embodiment of the present invention a wiring pattern made of metal that occupies 10 of the entire area of the wiring layer pattern will predominantly contribute to the thermal conductivity on the entire surface of the wiring layer and thus the insulative material that covers the majority of the area 90 will not measurably contribute to the thermal conductivity the wiring layer acts similar to a thermal resistor thus a thinner wiring layer is preferable fig6 is a representation of two simple line graphs showing the relationship between the thickness of the wiring layer and thermal resistance in the thin.