Multilayered printed circuit board

Abstract

The present invention is to provide a multilayered printed circuit board free from cracks attributed to thermal expansion difference between a solder resist layer and another part and a multilayered printed circuit board of the present invention comprises a conductor circuit and a resin insulating layer serially formed on a substrate in an alternate fashion and in repetition and a solder resist layer formed as an outermost layer, and the solder resist layer contains an inorganic filler.

1 . A multilayered printed circuit board comprising:
 a conductor circuit and a resin insulating layer serially formed on a substrate in an alternate fashion and in repetition;   and a solder resist layer formed as an outermost layer,
 wherein said solder resist layer is comprising a polyolefin type resin. 
   
     
     
         2 . The multilayered printed circuit board according to  claim 1 , wherein said solder resist layer has a dielectric constant of 3.0 or lower at 1 GHz. 
     
     
         3 . The multilayered printed circuit board according to  claim 1 , wherein said solder resist layer has a dielectric loss tangent of 0.01 or lower at 1 GHz. 
     
     
         4 . The multilayered printed circuit board according to  claim 1 , wherein said solder resist layer is comprising a cycloolefin type resin. 
     
     
         5 . The multilayered printed circuit board according to  claim 4 , wherein said cycloolefin type resin is a homopolymer or a copolymer of a monomer comprising 2-norbornene, 5-ethylidene-2-norbornene or their derivatives. 
     
     
         6 . The multilayered printed circuit board according to  claim 4 , wherein said cycloolefin type resin is a thermosetting cycloolefin type resin. 
     
     
         7 . The multilayered printed circuit board according to  claim 1 , wherein said resin insulting layer is comprising a polyolefin type resin or a polyphenylene type resin.