Chip packaging method and structure thereof

Abstract

The present invention relates to a chip packaging method and structure, in which bonding pads provided on the chip are connected by a plurality of metal wires via bonding, each of the metal wires is bending in the middle part to be higher than a predetermined height, and its ends are respectively electrically connected with two of the bonding pads. A molding layer is packaged on the chip and the molding layer is higher than the predetermined height. The molding layer is sliced at the predetermined height. Two upper breakpoints of each metal wire are exposed and a substrate is attached onto the molding layer. A plurality of circuit contacts of the substrate are respectively electrically coupled with the upper breakpoints. Whereby, the invention is capable of reducing the length of the metal wires in order to improve transmission speed, but also to reduce the volume of the packaging structure.

1 . A chip packaging method, comprising the following steps:
 (A) providing a chip, a plurality of bonding pads being provided on an upper surface thereof;   (B) connecting out a plurality of metal wires via bonding, in which a middle part of each of the plurality of metal wires is bent to be higher than a predetermined height, and two ends of each of the plurality of metal wires are respectively electrically connected to two of the plurality of bonding pads;   (C) packing a molding layer on the chip to cover at least a part of the plurality of metal wires, the molding layer being higher than the predetermined height;   (D) slicing the molding layer from the place of the predetermined height and cutting out the plurality of metal wires to expose two upper breakpoints of each of the plurality of metal wires; and   (E) attaching a substrate, disposed in advance with a plurality of circuit contacts, onto the molding layer, wherein the plurality of circuit contacts are correspondingly electrically coupled to the upper breakpoints of the plurality of metal wires, respectively.   
     
     
         2 . The chip packaging method as claimed in  claim 1 , wherein in the step (A), a lower surface of the chip is mounted on a carrier board. 
     
     
         3 . The chip packaging method as claimed in  claim 1 , further comprising a step after the step (D):
 (D 1 ) forming a plurality of metal pads on the molding layer, the plurality of metal pads being respectively corresponding to the upper breakpoints of the plurality of metal wires;   wherein in the step (E), the plurality of circuit contacts of the substrate are respectively electrically connected to the upper breakpoints of the plurality of metal wires through the plurality of metal pads.   
     
     
         4 . The chip packaging method as claimed in  claim 3 , wherein the step in (D 1 ) of forming a plurality of metal pads on the molding layer includes formation by way of passing a tin slot. 
     
     
         5 . The chip packaging method as claimed in  claim 1 , wherein the step in (D) of slicing the molding layer is at least selected from a group formed by laser cutting, diamond knife cutting and grinding wheel cutting. 
     
     
         6 . The chip packaging method as claimed in  claim 1 , further comprising a step after the step (E):
 (F) forming a plurality of ball pads on the upper surface of the substrate, the plurality of ball pads being respectively electrically coupled to the plurality of circuit contacts.   
     
     
         7 . A chip packaging structure, comprising:
 a chip, including an upper surface and a lower surface, the upper surface being provided with at least a bonding pad;   at least a metal wire, including a first end and a second end, the first end being electrically connected to the at least a bonding pad of the chip;   a molding layer, being packaged to cover the chip and the at least a metal wire, the second end of the at least a metal wire being exposed to an upper surface of the molding layer; and   a substrate, attaching onto the upper surface of the molding layer, a lower surface of the substrate including at least a circuit contact, which is correspondingly electrically coupled to the second end of the at least a metal wire.   
     
     
         8 . The chip packaging structure as claimed in  claim 7 , further comprising a carrier board, the lower surface of the chip being mounted on the carrier board. 
     
     
         9 . The chip packaging structure as claimed in  claim 8 , further comprising a fastening layer for fastening between the lower surface of the chip and the carrier board. 
     
     
         10 . The chip packaging structure as claimed in  claim 7 , wherein the upper surface of the molding layer further comprises at least a metal pad, and the at least a circuit contact of the substrate is electrically connected to the second end of the at least a metal wire through the at least a metal pad. 
     
     
         11 . The chip packaging structure as claimed in  claim 10 , wherein the at least a metal pad includes a tin-plated pad. 
     
     
         12 . The chip packaging structure as claimed in  claim 7 , wherein the lower surface of the substrate is further convexly provided with a leg pad, and the at least a circuit contact is electrically connected to the second end of the at least a metal wire through the at least a leg pad. 
     
     
         13 . The chip packaging structure as claimed in  claim 12 , further comprising an attaching layer, which is attached between the upper surface of the molding layer and the lower surface of the substrate, while not overlaying the at least a leg pad. 
     
     
         14 . The chip packaging structure as claimed in  claim 7 , wherein the upper surface of the substrate further comprises a ball pad, which is electrically coupled to the at least a circuit contact.