Flip chip package with anti-floating structure

Abstract

A flip chip package with an anti-floating structure includes a leadframe, a flip chip, and a plurality of solders. The leadframe includes a plurality of leads and a fastening part. At least one locking hole is formed on an upper surface of the fastening part. The flip chip includes an active surface, and at least one locking protrusion and a plurality of bumps formed on the active surface. The locking protrusion is correspondingly plugged into the locking hole to act as an anti-floating structure for the flip chip package. When the solders are used for connecting the bumps with the leads by reflowing, the anti-floating structure will prevent the flip chip from floating up, and the solders will not generate necking after reflowing.

1 . A flip chip package with an anti-floating structure, comprising:
 a chip carrier having an upper surface, a lower surface, a plurality of contacts and at least one locking hole, the contacts being exposed at the upper surface and the locking hole being exposed at the upper surface;   a flip chip having an active surface, at least one locking protrusion and a plurality of bumps, the locking protrusion and the bumps being formed on the active surface, the locking protrusion being plugged into the locking hole; and   a plurality of solders for connecting the bumps to the contacts.   
   
   
       2 . The flip chip package according to  claim 1 , wherein the chip carrier is a circuit substrate. 
   
   
       3 . The flip chip package according to  claim 2 , wherein the chip carrier comprises a dielectric layer and a copper layer, the dielectric layer having at least one first hole, and the copper layer being formed on the dielectric layer and having at least one second hole aligned with the first hole, thereby forming the locking hole. 
   
   
       4 . The flip chip package according to  claim 3 , wherein the aperture of the second hole of the copper layer is smaller than that of the first hole of the dielectric layer. 
   
   
       5 . The flip chip package according to  claim 1 , wherein the outside diameter of the locking protrusion is slightly larger than the size of the locking hole. 
   
   
       6 . The flip chip package according to  claim 1 , wherein the locking protrusion is used for grounding or thermal conducting. 
   
   
       7 . The flip chip package according to  claim 1 , wherein the height of the locking protrusion is larger than that of the bumps. 
   
   
       8 . The flip chip package according to  claim 1 , further comprising a molding compound for sealing the bumps and the locking protrusion. 
   
   
       9 . The flip chip package according to  claim 1 , further comprising a bonding agent applied into the locking hole, so as to fix the locking protrusion to the locking hole. 
   
   
       10 . The flip chip package according to  claim 1 , wherein the locking protrusion is formed at the center of the active surface of the flip chip. 
   
   
       11 . The flip chip package according to  claim 1 , wherein the locking protrusion is formed at the periphery or corner of the active surface of the flip chip.