Multilayer printed wiring board

Abstract

In a core substrate 30 , a ground through hole 36 E and a power through hole 36 P are disposed in the grid formation, so that electromotive force induced in X direction and Y direction cancel out each other. As a result, even if mutual inductance is reduced and a high frequency IC chip is loaded, electric characteristic and reliability can be improved without generating malfunction or error.

1 - 17 . (canceled) 
     
     
         18 . A multi-layer printed wiring board comprising:
 a core substrate comprising:
 a resin structure having a planar top resin surface and a planar bottom resin surface which is opposite to the planar top resin surface, 
 a plurality of conductive layers including a top conductive layer formed directly on the planar top resin surface, and a bottom conductive layer formed directly on the planar bottom resin surface, said top and bottom conductive layers each being a ground conductive layer, each being a power conductive layer, or being a ground conductive layer and power conductive layer respectively, and 
 a plurality of through holes in the core substrate and disposed so that a ground through hole and a power through hole are adjacent each other, wherein a distance between the ground through hole and the power through hole is in a range of 60 to 550 μm; 
   an interlayer insulating layer formed on the core substrate;   a conductive layer formed on the interlayer insulating layer; and   a plurality of via holes provided in the insulating layer and configured to provide electrical connection between the conductive layer and through holes.   
     
     
         19 . The multi-layer printed wiring board according to  claim 18 , wherein the ground through hole in the core substrate including two or more ground through holes and the power through hole including two or more power through holes, such that the ground through holes and the power through holes are disposed in a grid formation or in a staggered formation at adjacent positions. 
     
     
         20 . The multi-layer printed wiring board according to  claim 18 , wherein the diameter of the ground through hole is 50 to 500 μm and the diameter of the power through hole is 50 to 500 μm. 
     
     
         21 . The multi-layer printed wiring board according to  claim 18 , wherein at least one through hole of the ground through holes and the power through holes comprises two or more through holes in a stack structure through all layers of the multi-layer printed wiring board up to an outermost layer. 
     
     
         22 . The multi-layer printed wiring board according to  claim 18 , wherein the ground through hole and the power through hole are disposed just below an IC chip. 
     
     
         23 . The multi-layer printed wiring board according to  claim 18 , wherein a thickness of each of the top and bottom conductive layers on the core substrate is larger than a thickness of the conductive layer on the interlayer insulating layer. 
     
     
         24 . The multi-layer printed wiring board according to  claim 18 , wherein assuming that the thickness of the conductive layers on the core substrate is α1 and a thickness of the conductive layer on the interlayer insulating layer is α2, α2<α1≦40α2. 
     
     
         25 . The multi-layer printed wiring board according to  claim 24 , wherein the α1 is in a relation of 1.2α2≦α1≦40α2. 
     
     
         26 . The multi-layer printed wiring board according to  claim 23 , wherein each of the plurality of conductive layers of the core substrate is a conductive layer for power or conductive layer for grounding. 
     
     
         27 . The multi-layer printed wiring board according to  claim 18 , wherein a capacitor is mounted on the surface thereof. 
     
     
         28 . The multi-layer printed wiring board according to  claim 18 , wherein the core substrate is a multi-layer core substrate with said plurality of conductive layers comprising three or more conductive layers including a thick conductive layer as an inner layer of the multi-layer core substrate, and said top and bottom conductive layers, wherein
 each conductive layer of the core substrate is a conductive layer for power or a conductive layer for grounding.   
     
     
         29 . The multi-layer printed wiring board according to  claim 18 , wherein the core substrate is a multi-layer core substrate composed of three conductive layers including a thick conductive layer as an inner layer of the multi-core substrate, and said top and bottom conductive layers, wherein
 the inner conductive layer of the core substrate is a conductive layer for power or conductive layer for grounding, and at least one of the top or bottom conductive layer includes a signal line.   
     
     
         30 . The multi-layer printed wiring board according to  claim 28 , wherein a thickness of the conductive layer of the inner layer of the core substrate is larger than a thickness of the conductive layer on the interlayer insulating layer. 
     
     
         31 . The multi-layer printed wiring board according to  claim 29 , wherein the conductive layer in the inner layer of the core substrate comprises two or more layers. 
     
     
         32 . The multi-layer printed wiring board according to  claim 28 , wherein the core substrate is so constructed that the thick conductive layer is disposed as the inner layer and a thin conductive layer is formed as one of the top and bottom conductive layers.