Circuit board

Abstract

A circuit board with anti-EMI proofing for each component on the board includes a first outer wiring layer, electronic components mounted on the first outer wiring layer, and at least one electromagnetic shielding unit. Each electromagnetic shielding unit has a shielding layer and conductive posts formed on the shielding layer, the shielding layer and conductive posts defining a receiving space to house and shield one of the electronic components. An adhesive layer formed on the first outer wiring layer bonds each electromagnetic shielding unit to the first outer wiring layer.

What is claimed is: 
     
         1 . A circuit board comprising:
 a first outer wiring layer;   at least one electronic component mounted on the first outer wiring layer;   at least one electromagnetic shielding unit, each of the electromagnetic shielding unit comprising an electromagnetic shielding layer and at least two conductive posts formed on the electromagnetic shielding layer, the electromagnetic shielding layer and the conductive posts cooperatively defining a receiving space, the electromagnetic shielding unit mounted on the first outer wiring layer through the conductive posts, causing each of the electronic component to be received in the receiving space of a corresponding one of the electromagnetic shielding unit; and   an adhesive layer formed on the first outer wiring layer which connects each of the electromagnetic shielding unit to the first outer wiring layer.   
     
     
         2 . The circuit board of  claim 1 , wherein the first outer wiring layer comprises at least two solder pads, the conductive posts are connected to the solder pads. 
     
     
         3 . The circuit board of  claim 2 , wherein each electronic component comprises at least two electrodes, each of the electrodes is connected to one of the solder pads through a soldering ball. 
     
     
         4 . The circuit board of  claim 3 , wherein the soldering ball is made of solder paste, conductive silver paste, or conductive copper paste. 
     
     
         5 . The circuit board of  claim 1 , further comprising:
 an inner wiring layer;   a first dielectric layer;   a second dielectric layer, the first dielectric layer and the second dielectric layer formed on opposite surfaces of the inner wiring layer; and   a second outer wiring layer formed on the first dielectric layer;   wherein the first outer wiring layer is formed on the second dielectric layer;   
     
     
         6 . The circuit board of  claim 5 , further comprising:
 a first solder mask layer formed on the second outer wiring layer.   
     
     
         7 . The circuit board of  claim 5 , further comprising:
 a second solder mask layer formed on the electromagnetic shielding layer.   
     
     
         8 . The circuit board of  claim 5 , further comprising:
 at least one first conductive via defined in the first dielectric layer, the first conductive via electrically connecting the second outer wiring layer and the inner wiring layer to each other.   
     
     
         9 . The circuit board of  claim 5 , further comprising:
 at least one second conductive via defined in the second dielectric layer, the second conductive via electrically connecting the first outer wiring layer and the inner wiring layer to each other.   
     
     
         10 . The circuit board of  claim 5 , wherein a density of the inner wiring layer is less than a density of the first outer wiring layer.