Methods and Apparatus for a Substrate Core Layer

Abstract

A structure for a core layer of a substrate and a method for fabricating a core layer of a substrate are disclosed. The core layer comprises a molding compound encapsulating a die or a plurality of dies, a dielectric layer on the surfaces of the molding compound, and a conductive layer on top of the dielectric layer. A through hole is formed through the dielectric layer and the molding compound, which may be filled with a metal plate. A laser via is formed similarly. Build-up layers may be assembled next to the core layer to form the substrate, which can be used to package dies.

What is claimed is: 
     
         1 . A structure for a core layer of a substrate, comprising:
 a first die with a die pad;   a molding compound encapsulating the first die while leaving an outer surface of the die pad uncovered by the molding compound;   a first dielectric layer on one surface of the molding compound and a second dielectric layer on another surface of the molding compound;   a first conductive layer on top of the first dielectric layer and a second conductive layer on top of the second dielectric layer;   a hole through the first dielectric layer, the second dielectric layer, and the molding compound, the hole filled with a metal plate; and   a laser via formed through the first dielectric layer and connected to the die pad.   
     
     
         2 . The structure of  claim 1 , wherein the laser via is connected to the metal plate by way of the first conductive layer. 
     
     
         3 . The structure of  claim 1 , further comprising a plurality of die pads for the first die, and a plurality of laser vias through the first conductive layer and the first dielectric layer connected to the plurality of die pads. 
     
     
         4 . The structure of  claim 1 , further comprising a plurality of holes through the first dielectric layer, the second dielectric layer, and the molding compound, which are filled with a plurality of metal plates. 
     
     
         5 . The structure of  claim 1 , further comprising
 a second die with a die pad, where the molding compound encapsulates the second die separated from the first die while leaving an outer surface of the die pad of the second die uncovered by the molding compound; and   a second laser via through the first conductive layer and the first dielectric layer connected to the die pad of the second die.   
     
     
         6 . The structure of  claim 1 , wherein the first dielectric layer comprises of Ajinomoto Build-up Film (ABF), Benzocyclo-buthene (BCB), or other similar material. 
     
     
         7 . The structure of  claim 1 , wherein the first conductive layer with the first dielectric layer and the second conductive layer with the second dielectric layer comprise of resin coated copper (RCC) or other similar material. 
     
     
         8 . The structure of  claim 1 , wherein the first conductive layer comprises a plurality of conductive sub-layers and the second conductive layer comprises a plurality of conductive sub-layers. 
     
     
         9 . The structure of  claim 8 , wherein the plurality of conductive sub-layers of the first conductive layer and the plurality of conductive sub-layers of the second conductive layer are formed at different times. 
     
     
         10 . The structure of  claim 1 , further comprising a build-up layer on one side of the structure to form the substrate. 
     
     
         11 . The structure of  claim 10 , further comprising another build up layer on another side of the structure to form the substrate. 
     
     
         12 . The structure of  claim 1 , further comprising an additional die connected to the laser via by way of a connection device. 
     
     
         13 . The structure of  claim 1 , further comprising an additional die connected to the metal plate . by way of a connection device. 
     
     
         14 . A method for fabricating a core layer of a substrate, comprising:
 placing a first die with a die pad on top of a peelable tape covering a base while the die pad is in contact with the tape;   encapsulating the first die and the die pad using a molding compound;   removing the base and the peelable type;   forming a first dielectric layer on one surface of the molding compound and a second dielectric layer on another surface of the molding compound;   placing a first conductive layer on top of the first dielectric layer and a second conductive layer on top of the second dielectric layer;   forming a hole through the first conductive layer, the second conductive layer, the first dielectric layer, the second dielectric layer, and the molding compound;   forming a laser via through the first conductive layer and the first dielectric layer connected to the die pad of the first die;   plating the hole and laser via with a metal plate.   
     
     
         15 . The method for  claim 14 , further comprising:
 attaching a first photo resist film covering the metal plate, the laser via, and the first conductive layer;   attaching a second photo resist film covering the metal plate and the second conductive layer;   etching the first conductive layer on areas not protected by the first resist film;   etching the second conductive layer on areas not protected by the second resist film; and   removing the first resist film and the second resist film.   
     
     
         16 . The method for  claim 15 , further comprising:
 assembling a build-up layer covering the metal plate, the first conductive layer, and the laser via, or assembling a build-up layer covering the metal plate and the second conductive layer.   
     
     
         17 . The method for  claim 14 , further comprising
 placing a second die with a die pad on top of the peelable tape covering the base while the die pad of the second die is in contact with the tape;   forming the molding compound on top of the peelable tape, the first die, and the second die, which encapsulates the first die and the second die while separating the first die and the second die by the molding compound; and   forming a second laser via through the first conductive layer and the first dielectric layer connected to the die pad of the second die.   
     
     
         18 . A method for fabricating a core layer of a substrate, comprising:
 placing a first die with a die pad on top of a peelable tape covering a base while the die pad is in contact with the tape;   forming a molding compound on top of the peelable tape and on top of the first die which encapsulates the first die;   removing the base and the peelable tape;   forming a first dielectric layer on one surface of the molding compound and a second dielectric layer on another surface of the molding compound;   forming a through hole through the first dielectric layer, the second dielectric layer, and the molding compound, drilling a via through the first dielectric layer connected to the die pad of the first die;   electroless plating a first conductive layer over the first dielectric layer, the second dielectric layer, the through hole, and the via;   attaching a resist film covering the electroless plated first conductive layer;   patterning and exposing the resist film to form a pattern;   plating a second conductive layer over the through hole, the via, and over the first conductive layer which are over the first dielectric layer and the second dielectric layer, based on the pattern of the resist film;   removing the resist film; and   etching the first conductive layer and the second conductive layer to remove the first conductive layer on places where only the first conductive layer has been plated.   
     
     
         19 . The method for  claim 18 , further comprising assembling a build-up layer covering the second conductive layer. 
     
     
         20 . The method for  claim 18 , wherein the first dielectric layer comprises of ABF or BCB or other similar material.