Method for decapsulating package

Abstract

A method for decapsulating a package is provided. The method comprises steps of providing a package having a chip therein, wherein the chip has an active surface and a rear surface. Further, the package further comprises a heat sink, a plurality of solder bumps, a substrate, an underfill and a plurality of solder balls. The method further comprises removing the heat sink and removing the substrate together with the solder balls. A dry etching process is performed to remove a portion of the underfill. A wet etching process is performed to remove the rest portion of the underfill. A thermal process solder bump removal process is performed to melt the solder bumps and then a solder bump removal process is performed to remove the melted solder bumps from the active surface of the chip.

1 . A method for removing an underfill from a chip, comprising:
 providing a chip having an active surface, wherein a plurality of solder bumps are disposed on the active surface of the chip and an underfill is disposed over the active surface and filling between the solder bumps;   performing a dry etching process in an inert-gas environment to remove a portion of the underfill; and   performing a wet etching process to remove the rest portion of the underfill.   
   
   
       2 . The method of  claim 1 , wherein the dry etching process includes a reaction ion etching process. 
   
   
       3 . The method of  claim 1 , wherein the inert-gas environment includes an argon-gas environment. 
   
   
       4 . The method of  claim 1 , wherein the wet etching process is performed with the use of a fuming nitric acid. 
   
   
       5 . The method of  claim 1 , wherein the wet etching process is performed at a temperature of about 60˜100° C. for about 30 seconds˜5 minutes. 
   
   
       6 . The method of  claim 1  further comprising performing a purging process to clean the chip by using nitrogen gas. 
   
   
       7 . A method for removing solder bumps from a chip, comprising:
 providing a chip having an active surface, wherein a plurality of solder bumps are disposed on the active surface;   performing a thermal process to melt the solder bumps; and   performing a solder bump removal process to remove the melted solder bumps from the active surface of the chip.   
   
   
       8 . The method of  claim 7 , wherein the solder bump removal process includes a physical stripping-away process. 
   
   
       9 . The method of  claim 8 , wherein the physical stripping-away process is selected from a group consisting of a disturbing method, a gravity method, suction method, ultrasonic method and a combination thereof. 
   
   
       10 . The method of  claim 7 , wherein, at a pressure of about 1 atm, the thermal process is performed at a temperature of about 100˜320° C. 
   
   
       11 . The method of  claim 7 , wherein the thermal process is performed in a thermal liquid type system. 
   
   
       12 . The method of  claim 11 , wherein the thermal liquid type system employs a vacuum oil.