Xilinx, Inc.
Chip package assembly with composite stiffener

Abstract:

A chip package assembly and method for fabricating the same are provided which utilize a composite stiffener selected to provide excellent resistance to warpage without detrimentally imposing excessive stress on a package substrate of the package assembly. In one example, the chip package assembly includes an integrated circuit die stacked on a top surface of a package substrate, and a composite stiffener coupled to a first edge of the package substrate. The composite stiffener includes a first stiffener member and a second stiffener member. The first stiffener member has a bottom surface bonded to the top surface of the package substrate. The second stiffener member is disposed over the first stiffener member. The second stiffener member has a bottom surface bonded to the top surface of the package substrate. The second stiffener member has a Young's modulus that is less than a Young's modulus of the first stiffener member.