Package structure and fabrication method thereof

Abstract

A method for fabricating a package structure is provided, which includes the steps of: forming a first insulating layer on a carrier; forming a dielectric body on the first insulating layer, wherein the dielectric body has a first surface formed on the first insulating layer and a second surface opposite to the first surface, and a circuit layer and a plurality of conductive posts formed on the circuit layer are embedded in the dielectric body; forming a second insulating layer on the second surface of the dielectric body, wherein the glass transition temperature of the first insulating layer and/or the second insulating layer is greater than 250° C.; and removing the carrier. Since the glass transition temperature of the first or second insulating layer is greater than that of the dielectric body, the package structure has a preferred strength to avoid warping, thereby dispensing with a support member.

What is claimed is: 
     
         1 . A method for fabricating a package structure, comprising the steps of:
 forming a first insulating layer on a carrier;   forming a dielectric body on the first insulating layer, wherein the dielectric body has a first surface coupled to the first insulating layer and a second surface opposite to the first surface, and a circuit layer and a plurality of conductive posts formed on the circuit layer are embedded in the dielectric body;   forming a second insulating layer on the second surface of the dielectric body, wherein a glass transition temperature of the first insulating layer and/or the second insulating layer is greater than 250° C.; and   removing the carrier.   
     
     
         2 . The method of  claim 1 , wherein the conductive posts are exposed from the second surface of the dielectric body. 
     
     
         3 . The method of  claim 2 , further comprising forming in the first insulating layer a plurality of first openings for exposing the circuit layer, and forming in the second insulating layer a plurality of second openings for exposing the conductive posts. 
     
     
         4 . The method of  claim 3 , further comprising forming a plurality of conductive bumps on the circuit layer exposed from the first openings of the first insulating layer. 
     
     
         5 . The method of  claim 4 , wherein the conductive bumps is 50 um in height. 
     
     
         6 . The method of  claim 1 , further comprising disposing a semiconductor element on the first insulating layer, wherein the semiconductor element is electrically connected to the circuit layer. 
     
     
         7 . The method of  claim 6 , further comprising forming an encapsulant on the first insulating layer to encapsulate the semiconductor element. 
     
     
         8 . The method of  claim 7 , wherein the encapsulant has a thickness between 20 and 180 um. 
     
     
         9 . The method of  claim 1 , wherein a thickness of the first insulating layer or the second insulating layer is between 1 and 20 um. 
     
     
         10 . The method of  claim 1 , wherein the glass transition temperature of the first insulating layer and/or the second insulating layer is greater than 400° C. 
     
     
         11 . The method of  claim 1 , wherein the first insulating layer and/or the second insulating layer are made of polyimide, (PI), polyamide-imide (PAI) or polybenzimidazole (PBI). 
     
     
         12 . A package structure, comprising:
 a dielectric body having opposite first and second surfaces;   a circuit layer embedded in the dielectric body;   a plurality of conductive posts formed on the circuit layer and embedded in the dielectric body;   a first insulating layer formed on the first surface of the dielectric body; and   a second insulating layer formed on the second surface of the dielectric body,   wherein a glass transition temperature of the first insulating layer and/or the second insulating layer is greater than 250° C.   
     
     
         13 . The structure of  claim 12 , wherein the conductive posts are exposed from the second surface of the dielectric body. 
     
     
         14 . The structure of  claim 13 , wherein the first insulating layer has a plurality of first openings for exposing the circuit layer, and the second insulating layer has a plurality of second openings for exposing the conductive posts. 
     
     
         15 . The structure of  claim 14 , further comprising a plurality of conductive bumps formed on the circuit layer exposed from the first openings of the first insulating layer. 
     
     
         16 . The structure of  claim 15 , wherein the conductive bumps is 50 um in height. 
     
     
         17 . The structure of  claim 12 , further comprising a semiconductor element disposed on the first insulating layer and electrically connected to the circuit layer. 
     
     
         18 . The structure of  claim 17 , further comprising an encapsulant formed on the first insulating layer for encapsulating the semiconductor element. 
     
     
         19 . The structure of  claim 18 , wherein the encapsulant has a thickness between 20 and 180 um. 
     
     
         20 . The structure of  claim 12 , wherein a thickness of the first insulating layer or the second insulating layer is between 1 and 20 um. 
     
     
         21 . The structure of  claim 12 , wherein the glass transition temperature of the first insulating layer and/or the second insulating layer is greater than 400° C. 
     
     
         22 . The structure of  claim 12 , wherein the first insulating layer and/or the second insulating layer are made of polyimide, (PI), polyamide-imide (PAI) or polybenzimidazole (PBI).