Patent ID: 6403401
Filing Date: 2002-06-11
Classification: H01L,H05K

Abstract:
A method of assembling a ball grid array assembly having a metal heatsink, comprising the steps of:providing a square or rectangular shaped metal heat sink in addition to providing a square or rectangular shaped laminate substrate whereby said metal heat sink and said laminate substrate are aimed at packaging ball grid array devices whereby further said heat sink has a laminate substrate attach surface and a heat sink marking surface whereby further said laminate substrate has a heat sink attach surface and a die attach surface; applying a layer of epoxy coat to said marking surface of said heat sink; applying a first layer of adhesive to said heat sink attach surface of said laminated substrate; attaching said heat sink to said laminate substrate by overlying said heat sink over said first layer of adhesive; applying a second layer of adhesive to die attach surface of said laminate substrate; providing a layer of interconnect tracings over said second layer of adhesive that has been applied to said laminate substrate said interconnect tracings having been provided with contact pads; providing a solder mask over said layer of interconnect tracings; inserting contact balls within said solder mask such that said solder balls overlay contact pads in said layer of interconnect tracings; electrically connecting said contact balls with said contact pads in said layer of interconnect tracings by reflow of said contact balls; encapsulating said ball grid array assembly thereby protecting said ball grid array assembly form environmental damage; providing identification markings on said marking surface of said heat sink; and performing inspection of said ball grid array assembly.