Multilayered printed circuit board useful in semiconductor device, comprises an internal magnetic layer, an internal conductive layer, a dielectric layer, a signal layer formed on the dielectric layer, and a cable bushing

摘要

The multilayered printed circuit board useful in semiconductor device, comprises an internal magnetic layer out of magnetic material, an internal conductive layer, dielectric layers (310, 341, 342), signal layers (351, 352) formed on the dielectric layers so that the dielectric layer is positioned between the signal layer and the conductive layer, and a cable bushing having internal and external surface. The signal layer is made of conductive material. The conductive layer has a measuring layer (321) or a power supply layer (322). The multilayered printed circuit board useful in semiconductor device, comprises an internal magnetic layer out of magnetic material, an internal conductive layer, dielectric layers (310, 341, 342), signal layers (351, 352) formed on the dielectric layers so that the dielectric layer is positioned between the signal layer and the conductive layer, and a cable bushing having internal and external surface. The signal layer is made of conductive material. The conductive layer has a measuring layer (321) or a power supply layer (322). The conductive layer has a first surface on which the magnetic layer is formed and a second surface on which the dielectric layer is formed. The magnetic layer is formed on the internal or external surface of the bushing and has a thickness (t) and a minimum length (L) on its surface. The magnetic layer is thinly formed so that the conditions are fulfilled and consists of magnetic units and ferrite film (331), which is formed directly on the conductive layer by a power less plating process. The conditions are t= 50mu m and L/t 1000. Each magnetism allocates and is formed through magnetic coupling of the magnetic units together under use of a strong interaction. The magnetic layer has an imaginary part-permeability (mu ) on the surface along a determined direction and the product (mu x t) of the permeability and the thickness (t) is larger than 10 mu m. The magnetic layer is formed under effect of chemical bond or van der Waals force and is formed parallel to a determined plain that is defined by a first and a second direction that are vertical to each other. The magnetic layer has a first and second permeability along the first and second direction. The permeabilities fulfill the expression of 0.5= x= 2.0, where x is a ratio of the first and the second permeability. The magnetic layer has a resistance of 0.1 omega cm or more in direct current and a permeability distribution property caused by ferromagnetic resonance. The ferrite film consists of a metal oxide composition, which is represented by a formulae of Fe aNi bZn cCo d, where a+b+c+d=3.0, 2.1= a= 2.7, 0.1= b= 0.3, 0.1= c= 0.7 and 0= d= 1.15.